Get started and FAQ

1. About this guide

1.1 This guide explains, in plain language, how RUST50/50 ("RUST50", "the site", "we", "us") works and how to use it safely. The site is operated by Rust50 Entertainment Ltd. It is help text. The binding rules are in the Terms and Conditions ("Terms") and the documents they refer to. If this guide and those documents say different things, the binding documents apply, in the order of precedence set out in Terms clause 1.2.

1.2 While the site is in test mode, everything described as a trade, deposit or payout is simulated inside the site, as set out in the notice above. Real Steam trading is switched off on the server and cannot be switched on from any page of the public site.

1.3 Where this guide says "at launch", it describes how the site is designed to work once real Steam trading is switched on. Some protections described here are not built yet. They are marked with a drafting note, and they must exist before real trading starts.

1.4 This guide is written in English. Amounts are in US dollars (USD) and describe item values, not money held by the site.

1.5 The version and effective date are shown at the top of this page. When a change to the Terms affects your rights, you will be told at sign-in and asked to accept the new version before you play again.

2. Key terms

2.1 These words have the following meanings in this guide.

• Round (also "coinflip" or "game"): one contest between two players. Each round has a public ten-digit round number, for example #4817305926.
• Creator: the player who opens a round, picks Black or White and stakes first.
• Joiner: the player who takes the other side by staking items worth close to the creator's stake (see section 12).
• Stake: the items a player puts into a round. The stake value is the total item value of those items.
• Pot: all items staked by both players. The pot value is the creator's stake value plus the joiner's stake value.
• Win chance: a player's share of the pot value. Equal stakes give each player exactly 50%.
• House fee (shown on the site as the "item fee"): the whole items the operator keeps from the pot when a round settles, worth as close as possible to, but not more than, 8% of the pot value, with the 8% cap calculated to the nearest cent (section 15).
• Payout: the Steam trade offer that sends the winner every pot item that was not kept as the house fee.
• Refund: the Steam trade offer that returns a creator's items when an open round is cancelled.
• Trade offer: Steam's way of moving items between accounts. You accept it in Steam and confirm it with Steam Guard.
• Bot account: a Steam account owned or controlled by the operator that sends trade offers automatically and holds staked items while a round runs.
• Trade URL: your personal Steam link that allows the bot accounts to send you trade offers.
• Item value: the USD value given to an item for the game, taken from the Steam Community Market (section 10).
• Server seed, commitment, client seed, nonce and roll: the values that decide and prove each result (section 17).
• Test mode: the current public mode, in which items and trades are simulated.

3. What RUST50/50 is

3.1 RUST50/50 is a peer-to-peer coinflip for cosmetic items from the game Rust. These are Steam Community items for Rust (Steam app 252490). Two players stake items, a coin decides the winner, and the winner receives the pot less the house fee. You play against another player, not against the operator; the operator's income is the house fee.

3.2 In short, a round works like this:

1. The creator picks Black or White and stakes items worth USD 1 to 5,000, up to 25 items.
2. A joiner takes the other side by staking items worth within 6% of the creator's stake, also up to 25 items.
3. Each player's chance of winning equals their share of the pot value.
4. When both stakes are confirmed, a 4-second countdown runs and the coin is animated. The result itself was fixed by a provably fair calculation before the coin moved.
5. The operator keeps whole items worth as close as possible to, but not more than, 8% of the pot value, with the 8% cap calculated to the nearest cent. The winner receives everything else.

3.3 To play at launch you will need: a Steam account that can trade, with the Steam Guard Mobile Authenticator switched on; a public Steam inventory containing tradable Rust items that have an item value; your Steam trade URL saved on your Profile; and you must meet the eligibility rules in section 4.

3.4 RUST50 deals only in items. There are no cash deposits, no cash withdrawals, no cryptocurrency and no site balance or wallet. Items go in by Steam trade offer and come out by Steam trade offer. The operator does not buy items from you, sell items to you or convert items into money.

3.5 A different fee model has been considered, in which winnings would stay on the site and a fee of 5% or 8% would be charged only when you cash out. That model is not active. Everything in this guide describes the current model, where the fee is taken in items from each pot at settlement.

3.6 RUST50/50 is not affiliated with, endorsed by or sponsored by Valve Corporation or Facepunch Studios. Steam is a trademark of Valve Corporation and Rust is a trademark of Facepunch Studios. We use these names only to describe the items and services involved.

4. Who can play

4.1 Age. You must be at least 18 years old, or older if the age of majority or the legal gambling age where you live is higher. Steam allows accounts from age 13, so having a Steam account does not show that you are old enough.

4.2 Location. You may only play where online gambling with items is lawful for you. You may not play from a restricted territory listed in the Terms, and you may not use a VPN, proxy or any other tool to hide where you are.

4.3 One person, one account, your own play. Each person may have one account. You must play only for yourself, with items you are entitled to use, and not on behalf of anyone else. Accounts may not be sold, lent, shared or transferred.

4.4 People who may not play. You may not play if you are self-excluded or otherwise barred from gambling, if you do not have control over your gambling or your finances (for example during bankruptcy), or if you already know the outcome of a round. Employees, directors and other key persons of the operator, and any account they control, may not play real rounds. Test bots and other operator test accounts never take part in real rounds.

4.5 Identity checks. At launch the operator will need your full name, residential address and date of birth, and will screen players against sanctions and politically exposed person lists. Documents may be requested, for example when the total item value you have deposited and received reaches the level set by the anti-money-laundering regulations of the Curaçao Gaming Authority (CGA). See the AML and KYC Policy.

4.6 If you are not eligible. If we find that you are not eligible, your account will be closed. The Terms explain what then happens to rounds and items, including the special rules that apply if a player is found to be under age.

5. Staying safe

5.1 Check the address. The official site is https://rust50.com. The old preview address (egirl.sx/rust50) only redirects there. Before you sign in, check that the address bar shows exactly rust50.com and that the connection is secure (the address starts with https://). Scam sites copy names with an extra letter, a hyphen or a different ending (such as .gg, .net or .io). Bookmark the real address and use the bookmark.

5.2 Never share these. Nobody from RUST50 will ever ask for, and you should never give anyone:

• your Steam password;
• Steam Guard codes (the 5-character codes from the Steam Mobile app or from email) or Steam recovery codes;
• a Steam Web API key;
• a QR code or link that signs you in to Steam on another device;
• screenshots of your Steam Mobile app confirmations.

5.3 Sign in only on Steam's own page. "Sign in with Steam" takes your whole browser tab to https://steamcommunity.com/openid/login; it does not open a pop-up. Check the address bar of that page. Some phishing sites draw a fake Steam sign-in box inside their own page. If a "Steam" sign-in appears as a box or pop-up inside another page, or the address bar does not show steamcommunity.com, do not type anything. If in doubt, close it, open steamcommunity.com yourself, sign in there, then return to rust50.com.

5.4 Ignore messages that come to you. RUST50 support does not contact players through Steam friend requests, Steam chat, Discord or other private messages. Support writes only by email, from the addresses listed in section 22, such as support@rust50.com. Treat any message offering free skins, a giveaway, a "verification" trade, an off-site deal or help with a "stuck" payout as a scam, even if it uses our name or logo.

5.5 The API key scam. Someone who obtains a Steam Web API key for your account can watch your trade offers, cancel real ones and send you copies from lookalike accounts. Never create a key because a website or person asks you to. Check steamcommunity.com/dev/apikey while signed in to Steam, and revoke any key you did not create yourself.

5.6 Check every trade offer before you confirm it. At launch, confirm an offer only if all of these are true:

1. You have just clicked "Create coinflip" or "Join coinflip", or you are expecting a payout or refund for a specific round.
2. The offer arrived while the round's timer was running (deposit and join offers are valid for 90 seconds).
3. The direction is right. A deposit or join offer only asks for your items and gives you nothing. A payout or refund only gives you items and asks for nothing.
4. The items are exactly the items you selected, by name and number.
5. The offer message names the site and the same round number shown on rust50.com.
6. The other account is one of the official bot accounts listed on the site.
7. The Steam Mobile app confirmation shows the same account and the same items.

If anything does not match, decline the offer and tell support. Never accept an offer that takes your items when you have not just started a round.

5.7 People in chat. Anyone in chat who claims to be staff and asks you to add them, trade with them or send items "for verification" is not staff. Report them to support.

5.8 If your Steam account is compromised. Change your Steam password, use "Deauthorize all other devices" in your Steam Guard settings, revoke any API key you did not create, cancel any trade offers you do not recognise and contact Steam Support. Then email support@rust50.com with your SteamID64 so that we can review recent rounds and trade offers on your account.

6. Signing in with Steam

6.1 At launch you sign in with the "Sign in with Steam" button. It uses Steam's OpenID sign-in: you enter your details on Steam's own page, and the sign-in tells us only which Steam account signed in (your SteamID64). We then read your public Steam display name and avatar from Steam. The site never sees, asks for or stores your Steam password or Steam Guard codes.

6.2 When you sign in we store your SteamID64, your Steam display name, the address of your Steam avatar image and the time your Steam sign-in was verified. When you save a trade URL, we store that too. We also keep records of your rounds and trade offers. The Privacy Policy lists everything we keep, why and for how long.

6.3 Your Steam display name and avatar are public on RUST50. Your name and avatar appear in the lobby and on round pages, including on the faces of the coin, and your name also appears in recent results, in the Round checker and next to your chat messages. Pick a Steam name you are happy for others to see.

6.4 The site sets a session cookie called rust50.sid on your first visit, whether or not you sign in, and replaces it with a new one when you sign in. It is sent only over a secure connection, cannot be read by page scripts, and lasts up to 24 hours from when it is set, after which you sign in again. Sessions are kept in the server's memory, so a service restart can also sign you out. You can sign out at any time: open the account menu under your name and choose "Sign out". See the Cookie and Local Storage Policy.

6.5 In test mode, the "Enter lobby" button opens a "Test lobby access" form that asks only for a test display name of up to 20 characters (letters, numbers, spaces, hyphens and underscores) and gives you a temporary test identity with sample items. No Steam account is needed, and this is not Steam sign-in. If the test site offers Steam sign-in, it is read-only: your real inventory can be displayed, but you cannot create or join rounds with it and nothing is transferred. Test sessions also end when the test service restarts.

7. Setting your trade URL

7.1 Your trade URL lets the operator's bot accounts send you trade offers without being on your Steam friends list. You must save it before you can create or join a round; otherwise the site shows "Set your Steam trade URL first".

7.2 To find it, open Steam, go to your Inventory, choose "Trade Offers", then "Who can send me Trade Offers?". The link is in the "Third-Party Sites" section. (Steam sometimes renames these menus; the link always starts with the address shown below.) It looks like this:

https://steamcommunity.com/tradeoffer/new/?partner=123456789&token=AbCd1234

7.3 Open your Profile, paste the link into the "Steam trade URL" field in the "Trade URL" section and choose "Save". The field appears only after you have signed in with Steam. The site checks the format ("That is not a valid Steam trade URL" if it is wrong) and checks that the link belongs to the Steam account you signed in with. A link that belongs to another account is refused with "Use the trade URL belonging to your signed-in Steam account."

7.4 If you choose "Create New URL" in Steam, your old trade URL stops working at once. Save the new one on your Profile straight away, or payouts and refunds to you will fail.

7.5 Treat your trade URL as private. It cannot be used to take items without your confirmation, but it lets anyone send you offers, which scammers use for fake offers.

7.6 In test mode, trade URL entry is not available ("Trade URL entry is unavailable for test accounts") and nothing is needed. Saving a trade URL never connects a trade bot or sends an offer while real trading is switched off.

8. Making your inventory public

8.1 To show you which items you can stake, the site reads your Rust inventory through Steam's public inventory service. It cannot read a private inventory, and you will see "Your Steam inventory is private."

8.2 To make it public, open your Steam profile, choose "Edit Profile", then "Privacy Settings". Set "My profile" to Public and "Inventory" to Public. Steam can take a few minutes to apply the change. Then open the item window on RUST50 and use the refresh button.

8.3 Only Rust items (Steam app 252490, inventory context 2) are shown. Items that Steam does not currently allow you to trade (for example some items you have just bought), and items already staked in another round, are shown greyed out and cannot be selected. An item without an item value can be selected but is refused when you submit (section 10.3).

8.4 A public inventory can be seen by anyone on Steam. That is Steam's setting, not ours. You can make it private again when you have finished, but you will not be able to create or join rounds while it is private.

9. Steam Guard and trade holds

9.1 Every deposit, join, payout and refund is a Steam trade. Steam requires trades to be confirmed with Steam Guard. Switch on the Steam Guard Mobile Authenticator in the Steam Mobile app before you play, so that you can accept and confirm offers within the 90-second window.

9.2 Steam may place a trade on hold, which delays it for several days. According to Steam Support, a trade can be held for up to 15 days if you do not use the Mobile Authenticator or switched it on less than 7 days ago. Cancelling a held trade can start a trading cooldown, and removing the authenticator or making some other security changes to your Steam account can also trigger trade restrictions. These are Steam's rules; Steam can change them, and neither RUST50 nor Steam Support can lift a hold for you.

9.3 A round goes ahead only after Steam reports the trade as complete. A trade that goes on hold is not credited, so the round cannot open or flip. In practice you cannot play while trades from your account are being held. If a held trade completes after a round's deadline, the round is marked "Trade needs review" and will not flip; contact support so that the items can be returned to you.

9.4 Valve can also restrict or suspend the operator's bot accounts. That would delay or prevent deposits, payouts and refunds. If it happens, the operator will post a notice on the site and tell affected players how their items will be returned.

9.5 Steam has a feature that lets players reverse recent trades for some games. As far as we know, it does not cover Rust today. If Valve extends it to Rust, the operator may need a settlement period before payouts, and the Terms will be updated first.

10. Item values

10.1 Every item has an item value in USD taken from the Steam Community Market. Item values are used to work out stake limits, joining ranges, win chances and the house fee.

10.2 You see each item's value, and the total "Selected value", before you confirm. The values used for a round are fixed when you submit your stake and are shown on the round. Values can change between rounds, so the same item can count for more or less in your next round.

10.3 An item without a value cannot be staked. The site shows "has no price and cannot be staked".

10.4 An item value is a reference figure for the game. It is not an offer by the operator to buy the item, and the operator does not guarantee that you could sell an item for that amount anywhere. Market prices move, and Steam charges its own market fees.

10.5 In test mode, values are reference prices set by the owner. They are illustrative, not live market quotes, and some are marked "(placeholder)".

11. Creating a round

11.1 Before you start

Sign in, save your trade URL (section 7), make sure your inventory is public (section 8) and keep the Steam Mobile app at hand.

11.2 Open the item window

Choose "Create new" in the "Your coinflip status" panel at the top of the lobby, or "Create a coinflip" when the lobby is empty. The "Create a coinflip" window opens and loads your inventory.

11.3 Pick your side

Choose "Black side" or "White side". Your avatar appears on the side you picked. The side has no effect on your chance; it only decides which face of the coin must land for you to win. The joiner automatically gets the other side.

11.4 Select items

Click an item to add it and click again to remove it. Use the search box to find items by name and the refresh button to reload your inventory. You can select up to 25 items. Items that are already in a round or not tradable are greyed out. The window shows your "Selected value" and an "Estimated pot at equal stakes", which is twice your selected value.

11.5 Or use Auto-select

Type an amount into "Target value" (USD 1 to 5,000) and choose "Auto-select". The site first looks for items worth exactly that amount. If there is no exact match, it looks for a set within 6% of the target (still within USD 1 to 5,000) and tells you, for example, "No exact match; this set is within 6% of 10.00". Auto-select replaces your current selection, respects the 25-item limit and skips locked items. It is a search helper, not a guarantee: if it reports no match, select items yourself.

11.6 Stake limits

Your selection must be worth at least USD 1 and at most USD 5,000. Outside that range, a warning appears and "Create coinflip" stays disabled.

11.7 Client seed (optional)

Open "Client seed" to type your own seed of up to 64 characters. Spaces at the start and end are removed. If you leave it empty, the site generates a random one (8 random bytes, shown as 16 hexadecimal characters). The client seed is published with the round and is one of the values that decide the result (section 17). Choosing your own lets you be sure that the site did not pick it.

11.8 Confirm and accept the trade

Choose "Create coinflip". The round appears with the status "Preparing items" and a timer ("Confirm 1:30"). At launch, a bot account sends you a trade offer asking for exactly the items you selected. Check it (section 5.6), accept it in Steam and confirm it in the Steam Mobile app before the timer ends.

11.9 What happens next

When Steam reports the trade as complete, the round becomes an "Open round" in the lobby, ready for a joiner. If you decline the offer in Steam, or do not accept it within 90 seconds, the offer is cancelled, the round is removed and nothing is staked: your items stay with you. This is also how you cancel at this stage, because there is no cancel button while the round shows "Preparing items" (section 16.2). If Steam cannot confirm that a lapsed offer was cancelled, the round is marked "Trade needs review" instead and will not open; contact support. If the site could not send the offer at all, the round is cancelled straight away and nothing leaves your inventory.

11.10 In test mode

Trades are simulated and confirm automatically after a short delay. You can have up to three active test rounds at a time. "Play test bot" lets an automated TEST BOT join your own open round with matching test items, so that you can see a full round. The lobby may also show "Sample round" entries opened by test identities, which are labelled TEST BOT.

12. Joining a round

12.1 Open rounds appear in the lobby. You can filter by "All games", "Open" or "Flipping" and sort by "Newest first", "Highest value" or "Lowest value". Choose "Join game" on an open round. You cannot join your own round.

12.2 You always take the side the creator did not pick. The join window shows it, for example "You take WHITE / match 47.00 - 53.00".

12.3 Value needed to join. Your stake must be worth within 6% of the creator's stake, either below or above. The lowest allowed value is the creator's value × 0.94 and the highest is the creator's value × 1.06, each rounded to the cent.

12.4 "Value needed to join" is filled in with the creator's stake and cannot be changed. "Auto-select" picks items from your inventory within the allowed range. You can also select items yourself; "Join coinflip" stays disabled until your selection is in range.

12.5 Your win chance is shown before you confirm: your stake value divided by (your stake value + the creator's stake value). For example, USD 49.00 against USD 50.00 gives you 49/99 = 49.5%, and the creator 50.5%.

12.6 Choose "Join coinflip". The round shows "Matching items" and nobody else can join while your trade is pending. At launch a bot sends you a trade offer for exactly your selected items. Accept and confirm it within 90 seconds.

12.7 If you decline the offer or the 90 seconds run out, your join lapses, your items stay with you and the round becomes open again for other players. If someone else started joining a moment before you, you will see "Someone else is joining this game".

13. The countdown and the coin

13.1 As soon as Steam reports the joiner's trade as complete, the result is calculated from the values that were committed when the round was created (section 17). The round then shows "Starting soon" and a 4-second countdown ("Flip in 4").

13.2 After the countdown, the coin animation runs: a spin followed by a slowing landing, which together last several seconds. The animation is cosmetic, and the result was fixed before it started. Its two faces show the two players' avatars. It lands on the winning side, and the winner is announced once it has landed. Anyone can watch with "Watch flip".

13.3 The animation only displays a result that already exists. Nothing you or anyone else does during the animation can change it. Closing the window, reloading the page or a slow connection does not affect the result or the payout. If reduced motion is switched on (section 20), the spin is skipped and the result is shown directly.

14. Results and payouts

14.1 When the coin has landed, the round shows "<name> wins" and a line such as "92.50 item value to the winner / 7.50 item fee". Finished rounds appear in "Recent results", in "History" (completed public rounds from the last 10 minutes) and in "My games" (your latest 50 rounds).

14.2 At launch, the payout is sent automatically as soon as the round settles, normally within seconds of the result. It is a trade offer from a bot account to the trade URL saved on your Profile, containing every item in the pot except the house fee items. Steam outages, rate limits or account restrictions can delay it.

14.3 A payout offer only gives you items and asks for nothing. Check it as described in section 5.6, then accept and confirm it in Steam within 3 days.

14.4 If a payout cannot be sent, is declined or expires, the items stay recorded against your win. The winner (or support) can ask for the payout offer to be sent again. Check that your trade URL is current first (section 7.4).

14.5 Prizes are paid only in items, never in money. The player who loses a round has nothing further to do; their staked items form part of the pot.

15. The house fee explained

15.1 How it is taken. When a round settles, the site looks at every item in the pot, from both players, and chooses the combination of whole items whose total value is as close as possible to, but not more than, 8% of the pot value, with the 8% cap calculated to the nearest cent (section 15.4). Those items are the house fee. The winner receives all the other items.

15.2 It can be lower than 8%, including zero. Items cannot be split. If no combination reaches exactly 8%, the fee is the closest total below it. If every item in the pot is worth more than 8% of the pot value, no item fits and the fee is zero.

15.3 It is not a percentage of profit. The fee is measured against the whole pot, not against what you gained. It can include items from either player's stake, including the winner's own items.

15.4 Rounding. The 8% limit is the pot value × 0.08, rounded to the nearest cent. Because of that rounding, the limit can be slightly above the exact 8% figure, by less than half a cent. For example, in a USD 1.94 pot, 8% is USD 0.1552 and the limit is USD 0.16. For pots of a few dollars or more the difference is negligible (see Fairness and Round Verification, section 14.8).

15.5 Examples. All amounts are item values in USD.

In example B, 7.00 + 1.50 would make 8.50, which is over the limit, so the best fit is 4.50 + 3.00 = 7.50. In example C, 25.00 + 20.00 would make 45.00, also over the limit, so the single 30.00 item is the closest fit.

15.6 Fee versus profit. In example B, if the creator wins, the gain before any fee is the joiner's 50.00 stake. A fee of 8% of that gain would be 4.00. RUST50's fee is measured against the whole 100.00 pot instead, and here it is 7.50, so the creator stakes 50.00, receives 92.50 and ends up 42.50 ahead.

15.7 What this means for you over time. The fee does not change anyone's win chance. It does mean that, on average, players get back less than they stake. Your expected return from a round is your stake × (1 − f), where f is the fee as a share of the pot. Because f is between 0% and 8% (marginally more in pots of only a few dollars, because of the rounding in section 15.4), the expected return is between about 92% and 100% of your stake, whatever the split of stakes. For example, with a 50.00 stake in example B (f = 7.5%), you have a 50% chance of receiving 92.50, an expected return of 46.25. This is an average over many rounds; any single round is either a win or a loss.

15.8 The fee actually taken is shown on every finished round. No fee is taken on a cancelled round.

16. Cancelling a round

16.1 Only the creator can cancel. Once the round is open with nobody joining ("Open round"), use the "Cancel round" button in the lobby or on the round page, and your items are returned (section 16.4).

16.2 While the deposit offer is still pending and the round shows "Preparing items", there is no cancel button. To cancel at this stage, decline the deposit trade offer in Steam, or let it expire by not accepting it within 90 seconds. The round is then removed and nothing is staked: nothing leaves your inventory.

16.3 A round cannot be cancelled once a joiner's trade is pending ("Matching items"), during the countdown or flip, or after it has finished.

16.4 An open round can be cancelled once it has been open for 30 minutes without a joiner (Terms clause 8.11). If you cancel an open round at launch, your items are returned by a refund trade offer containing exactly your items. Accept and confirm it in Steam. If a refund fails, is declined or expires, it can be sent again; ask support.

16.5 A joiner cannot cancel after choosing "Join coinflip", but if the joiner does not accept the offer within 90 seconds, the join lapses and the joiner keeps their items.

16.6 In test mode, cancelled items become available again immediately ("Round cancelled. Your items are available again.").

16.7 Repeatedly depositing items and cancelling without playing may be reviewed under the operator's anti-money-laundering procedures.

17. The Round checker

17.1 Every result can be checked by anyone. The site commits to a secret value before the result, reveals it afterwards, and publishes everything needed to recompute the winner. The full method is in Fairness and Round Verification; this section shows how to use it.

17.2 The values

• Server seed: 32 random bytes generated by the server for each round, shown as 64 hexadecimal characters. It stays secret until the round finishes.
• Server seed hash (the commitment): the SHA-256 hash of the server seed. It is published when the round is created, before anyone can know the result.
• Client seed: chosen by the creator, or 8 random bytes in hexadecimal if the creator left it empty.
• Nonce: for new rounds, the round's random ten-digit public number. Older rounds keep the nonce they were originally stored with; it is never rewritten.
• Stake values: the creator's and the joiner's stake values.

17.3 The calculation

1. Calculate HMAC-SHA256 with the server seed as the key and the text "client seed:nonce" as the message.
2. Take the first 8 hexadecimal digits of the result and read them as a whole number (0 to 4,294,967,295).
3. Divide that number by 0xffffffff (4,294,967,295). This is the roll, a number from 0 to 1.
4. Work out the creator's chance: creator value ÷ (creator value + joiner value).
5. If the roll is less than the creator's chance, the creator wins. Otherwise the joiner wins.

The server seed is used exactly as its 64 characters of text, both for the hash and as the HMAC key.

17.4 Worked example

These values are made up to show the method; they are not a real round.

• Server seed: a3f1c2d4e5b6978812345678abcdef0123456789abcdef0123456789abcdef01
• Commitment: 7bf8b9050658ddb8d2911ad91f589bbb1143d6933f1255e12199da837a810a02
• Client seed: lucky-seed-42; nonce: 4817305926; message: lucky-seed-42:4817305926
• HMAC-SHA256 begins 7c8d713e, which is 2,089,644,350; roll = 2,089,644,350 ÷ 4,294,967,295 = 0.4865332391
• Creator (Black) stakes 50.00 and joiner (White) stakes 49.00, so the creator's chance is 50 ÷ 99 = 0.5050505051
• 0.4865332391 is less than 0.5050505051, so Black, the creator, wins.

17.5 Using the Round checker

Open the Round checker from the "Round checker" link under the lobby or in the footer, or with "Check this round" on any round page. Enter the ten-digit round number, with or without "#", and choose "Find round".

• Before the result it shows the status, the commitment, the client seed, the nonce, the creator's side and stake and, once someone has joined, the joiner's side and stake, with a note that the seed will be revealed after the flip. "Verify result" stays disabled until the round has finished.
• After the result it also shows the revealed server seed, the recorded roll and the recorded winner, and fills in the proof. "Verify result" recomputes the hash, the roll and the winner in your own browser and compares them with the stored record. A match shows "Verified. Round #… matches its record."; any difference is reported as a mismatch.
• Manual check: you can type values yourself. The checker then tells you that the check is not linked to a stored round, and only compares the values you entered.
• The calculation in the checker runs in your own browser ("Calculated locally in this browser"); the site does not do it for you.

17.6 For the strongest check, copy the commitment while the round is still open, before the coin flips, and compare it with the revealed seed afterwards.

17.7 You can also check a round with any SHA-256 and HMAC-SHA256 tool. For example, in Node.js:

const c = require('crypto');
const seed = '<revealed server seed>';
console.log(c.createHash('sha256').update(seed).digest('hex')); // must equal the commitment
const h = c.createHmac('sha256', seed).update('<client seed>:<nonce>').digest('hex');
console.log(parseInt(h.slice(0, 8), 16) / 0xffffffff); // the roll

17.8 What the check proves. It proves that the server seed was fixed before the result and was not changed afterwards, and that the winner follows from the published values. It cannot by itself prove how the server chose its seed, and the server can calculate a round's roll once the round exists. That is why operator accounts, staff and test bots must never take part in real rounds (section 4.4). No administrator, promotion or test control can change a result, the odds, the seeds or a payout, and old fairness records are never rewritten.

18. Chat rules

18.1 The lobby chat is public. Anyone viewing the lobby can read it; you must be signed in to post.

18.2 Each message must be 1 to 280 characters. You can send at most 3 messages per 10 seconds; after that you see "Too many requests. Wait a moment and try again." Links are not allowed: messages containing "http://", "https://" or "www." are refused.

18.3 Be respectful. Do not:

• harass, threaten or abuse anyone, or post hateful or sexual content;
• spam, advertise, beg for items or offer trades or deals;
• post personal information about yourself or anyone else;
• impersonate staff, run scams or point people to other sites;
• arrange rounds with other players to pass items between accounts, or discuss ways around age, location or identity checks;
• encourage anyone to gamble more, chase losses or borrow to play.

18.4 Chat is a public conversation, not customer support. For help, use the contacts in section 22.

18.5 How long messages are kept. Only the latest 50 messages are kept, in the server's memory. Older messages drop off, and all messages disappear when the service restarts. Chat is not saved to the database.

18.6 Moderation. The operator can mute an account for 1 hour, 24 hours or 7 days, or ban it, and can lift a mute or a ban. Every action is recorded with a reason in an audit log. A muted player sees "Your chat access is temporarily muted."; a banned account can no longer use any signed-in feature. If you think an action was wrong, contact support or make a complaint (section 22).

19. Profile and referral codes

19.1 Your Profile shows your account (name, Steam ID and connection), your referral code and referral count, the name promotion check and your trade URL.

19.2 Your code. Your referral code is created automatically the first time you open your Profile page. The Profile shows it in the "Affiliates" section with a referral link you can copy. When someone opens your link, your code is filled in for them in the "Referred by" field on their Profile page and kept in that browser tab's session storage (rust50.pendingReferral) until it is applied or the tab is closed. It is never applied automatically; they must choose "Apply".

19.3 Applying a code. Enter another player's code under "Referred by" and choose "Apply". Each account can record one referral code, once; it cannot be changed or removed afterwards. Your own code is refused ("You cannot use your own referral code."), an unknown code is refused ("That referral code was not found."), and a second code is refused once one is recorded.

19.4 Counts are real. "Referred accounts" counts only referrals actually recorded. In test mode it includes test accounts.

19.5 No rewards are paid. The Profile shows a "2.5%" promotional reward eligibility field. It is inactive: no commission, credit or reward of any kind is paid or credited, and it never changes anyone's odds. Any future promotion will have its own terms, published with the Promotions and Referral Terms, which you would have to accept before taking part.

19.6 Name promotion. "Check Steam name" checks whether your Steam display name contains "rust50.com". This exists only for possible future promotions. It is inactive, earns nothing and does not affect odds. You do not need to change your name. The check works only for accounts signed in with Steam, so it is not available for test identities.

19.7 If you share your code, do not target anyone under 18, do not spam chat (links are blocked there anyway) and do not make misleading claims such as guaranteed wins or easy money.

20. Preferences

20.1 Open "Preferences" from the footer of the lobby. The sun or moon button in the header also switches between light and night themes.

• Appearance: Light, Night, or Use device setting (the default, which follows your device's light or dark mode).
• Reduced motion: shows a minimal coin animation that skips the spin and shows the result directly. The site also reduces motion automatically if your device is set to reduce motion, even when this switch is off.
• Result sound: off by default. When on, a short tone plays when a round you played in finishes.

20.2 The Profile page has its own sun or moon button that switches the theme in the same way.

20.3 Preferences are stored only in your browser, under the name rust50.preferences. They are not sent to our server. Each browser and device keeps its own settings, and clearing your browser data resets them. See the Cookie and Local Storage Policy.

21. Responsible gambling tools

21.1 Treat RUST50 as gambling, not as a way to earn. Only stake items you can afford to lose, decide your limit before you start, and never try to win back losses. Because of the house fee, players get back less than they stake on average (section 15.7).

21.2 At launch the full set of player-protection tools in the Responsible Gambling Policy (sections 10 to 16) will be available on your account: deposit, loss, single-stake and session limits, reality checks, time-outs (cooling-off) and self-exclusion. In short:

• Deposit limits: a daily, weekly or monthly limit on the total item value you can stake. A lower limit applies at once; a higher limit, or removing one, applies only after 7 days.
• Loss limits: a daily, weekly or monthly cap, in USD item value, on your net loss. A lower limit applies at once; a higher limit, or removing one, applies only after 7 days.
• Single-stake limits: a cap on the item value you can put into any one round, whether you create it or join it.
• Session limits: a limit of between 30 minutes and 8 hours of play. When you reach it, you cannot create or join rounds for the rest of that day (UTC).
• Cooling-off (time-out): a break of 24 hours, 7 days, 1 month or 3 months, started with one click and without asking anyone. It starts immediately, your account is locked for the whole period and it reopens automatically at the end.
• Self-exclusion: exclusion for 1, 3, 5 or 10 years, or permanently, completed online. It starts immediately and cannot be undone during the period, which is at least 12 months. It covers every site of the operator. Your SteamID64 and trade URL are blocked, any items held for you are returned by trade offer, and you are removed from all marketing.
• Reality checks: reminders every 15, 30 or 60 minutes of how long you have been playing and your results, which pause play until you respond.
• History: a full, timestamped record of your rounds since you opened your account.
• Self-assessment: a short questionnaire to help you judge whether your gambling is a problem.

21.3 A new limit or exclusion applies straight away, except to a round already in progress, which finishes (at most the 90-second trade window plus the countdown and flip).

21.4 Until the tools are on the site, email responsible-gambling@rust50.com to ask for a limit, a cooling-off period or self-exclusion. A request that makes your play safer is applied on receipt, and at the latest within 24 hours, at any time of day and on any day of the week. The operator will not try to talk you out of it or offer you anything to stay.

21.5 Warning signs. Take a break and consider getting help if you stake more than you planned, chase losses, borrow or sell things to play, hide your play from people close to you, feel anxious or irritable when not playing, or play to escape problems.

21.6 Where to get help. Free, confidential support is available from organisations such as GamCare (gamcare.org.uk), Gamblers Anonymous (gamblersanonymous.org), GambleAware (begambleaware.org) and, for residents of Curaçao, Fundashon pa Maneho di Adikshon (fma-curacao.com). Look also for a helpline in your own country. Parents can use filtering software to block gambling sites on shared devices.

21.7 The full policy is in the Responsible Gambling Policy.

22. Support and complaints

22.1 Support. Email support@rust50.com. We aim to reply within within 24 hours. To help us, include your SteamID64 (shown on your Profile), the round number, any Steam trade offer ID, the time of the problem and screenshots. Never send your password, Steam Guard codes or API keys.

22.2 Other contacts. Responsible gambling: responsible-gambling@rust50.com. Privacy and data requests: privacy@rust50.com. Identity checks: compliance@rust50.com.

22.3 Making a complaint. If support has not solved your problem, send a complaint to complaints@rust50.com. Complaints are free. You can complain up to 6 months after the round settled or the incident happened. Only the account holder can complain, and claims against the operator cannot be sold or transferred. You may write in English, Dutch or Papiamentu. Please give your name, address and place of residence, your SteamID64, the date of your complaint, the date of the event, the round number and a description.

22.4 Time limits. You will receive a written acknowledgement within one week, explaining how your complaint will be handled and how long it usually takes. A reasoned final decision is due in writing within 4 weeks; this can be extended once by up to 4 more weeks, with written notice before the first 4 weeks end. Complaints about responsible gambling, such as a self-exclusion that was not applied, are acknowledged within 2 days, and the operator will try to resolve them within 5 business days.

22.5 Independent dispute resolution. If you are not satisfied with the final decision, you can refer the dispute to the Cyprus Consumer Protection Service (Ministry of Energy, Commerce and Industry), an independent dispute-resolution service. It is free for you; the operator pays its costs. Complaints explains how a decision there affects any further legal steps.

22.6 The regulator. Where the operator holds a licence from the Curaçao Gaming Authority (see section 24.3), the CGA does not decide individual disputes between players and operators, but you can contact it about suspected licence breaches or other malpractice. The operator does not restrict your right to do so.

23. Troubleshooting

23.1 I did not receive a trade offer

• Check that the trade URL on your Profile is your current one (section 7.4).
• Look in Steam under Inventory, then "Trade Offers", then incoming offers. Mobile notifications can be slow.
• Check that your account can trade: no trade hold, cooldown or restriction, and Steam Guard switched on (section 9).
• Steam may be slow or down. If the site could not send the offer, the round is cancelled and nothing leaves your inventory.
• Never accept a lookalike offer from another account while you wait. Contact support with the round number.

23.2 My offer expired

Deposit and join offers are cancelled after 90 seconds. A creator's round is then removed with nothing staked, and a joiner's join lapses; in both cases your items stay with you and you can start again. If you accepted at the very last moment and Steam completed the trade after the deadline, the round is marked "Trade needs review" and will not flip; contact support so that the items can be returned. If a payout or refund offer expired, ask for it to be sent again (sections 14.4 and 16.4).

23.3 My inventory is private or items are missing

Make your inventory public (section 8.2), wait a few minutes and use the refresh button in the item window. Only Rust items are listed. Items that are not tradable yet, or are already in a round, are greyed out, and items without an item value are refused when you submit (section 8.3). The list is kept for up to a minute, so the refresh button is the quickest way to see a change.

23.4 Trade holds

If Steam is holding your trades, you cannot play until the hold ends (section 9). Only Steam controls holds.

23.5 The lobby does not load

The lobby uses a live connection. The indicator in the header shows "Live" when it works. If you see "Connecting to the lobby", "Reconnecting" or "The lobby could not connect. Refresh to retry." for a long time, check your internet connection, reload the page, and try turning off browser extensions that block live connections or scripts. Some workplace or school networks block them. After a service restart you may need to sign in again. If an action fails with "Your session check expired. Refresh the page and try again.", reload the page and repeat it.

23.6 Messages you may see

24. Frequently asked questions

About RUST50/50

24.1 Is this real gambling?

Once real trading starts, treat it as gambling. You stake items that can be traded for value on a result decided by chance, and you can lose them. Gambling law in Curaçao and elsewhere is likely to apply. In test mode nothing of value can be staked, won or withdrawn.

24.2 Who runs RUST50/50?

Rust50 Entertainment Ltd, registered with the Curaçao Chamber of Commerce under number HE 452139, at 28 Omonias Avenue, 1010 Nicosia, Cyprus. See Operator and Licence.

24.3 Is the site licensed?

Licence number HE 452139, issued 5 November 2026 by the Curaçao Gaming Authority, which you can check at https://www.nba.gov.cy. Rely on a licence only if the CGA's own check shows the same domain, rust50.com.

24.4 Is RUST50 part of Valve, Steam or Facepunch?

No. RUST50/50 is independent and is not affiliated with, endorsed by or sponsored by Valve Corporation or Facepunch Studios.

24.5 Does Valve allow sites like this?

Steam's own rules limit commercial use of Steam and list gambling among the activities they prohibit on Steam. Valve can restrict, delay or end trading on any account, including yours and the operator's bot accounts. RUST50 cannot reverse Valve's decisions. Consider this risk before you play.

24.6 Can I play from my country?

Only where it is lawful for you and not from a restricted territory listed in the Terms. Using a VPN or proxy to hide your location is not allowed.

24.7 Steam allows 13-year-olds. Why is RUST50 18+?

Because it is gambling. You must be 18 or the higher legal age where you live, whatever age Steam accepts.

Accounts and data

24.8 Can RUST50 see my Steam password?

No. You sign in on Steam's own page, and the sign-in tells us only your SteamID64. Your display name and avatar are then read from your public Steam profile.

24.9 What data do you keep about me?

Your SteamID64, display name, avatar address, trade URL, account status and times, your rounds and trade offers, referral records, Steam name check results and server logs. The Privacy Policy has the full list and retention periods.

24.10 Can I have more than one account?

No. One person may have one account. Signing in with another Steam account creates a separate account, which breaks this rule.

24.11 How do I close my account?

Email support@rust50.com with your SteamID64. Support will ask you to confirm that the account is yours, for example by signing in. Any items held for you are returned by trade offer first. Some records must be kept for a period after closure by law, as the Privacy Policy explains: for example, round, trade and fee records are kept for at least 5 years after each transaction, and identity check records for at least 5 years after the account is closed. If you want to stop because of your gambling, self-exclusion (section 21) is the stronger option.

24.12 Why might I have to prove my identity?

The CGA's anti-money-laundering regulations require identity checks. Full checks are needed once a player's deposits and withdrawals together reach XCG 4,000 (about USD 2,235). If item deposits and payouts count at their item value, one round at the maximum stake would pass that level. See the AML and KYC Policy.

24.13 Can staff see or change my rounds?

The owner console can view rounds read-only, mute or ban players with a recorded reason, and read the audit log. It cannot change a result, the odds, the seeds or a payout. Item values come from the Steam Community Market, chosen by the operator (section 10). The values used in a round are fixed when each stake is submitted, and no site control changes them afterwards.

Trading and items

24.14 Why do I have to accept a trade offer to create a round?

Your items must be held by a bot account while the round runs so that the winner can be paid automatically. Steam requires you to approve every trade yourself.

24.15 Why only 90 seconds?

So that rounds do not sit half-made and items are not tied up. If you miss the window, nothing is lost; start again.

24.16 Can I deposit money, crypto or items from other games?

No. Only Rust items with an item value can be staked. There are no cash or crypto deposits or withdrawals.

24.17 Is there a site balance?

No. Items are staked into one round and paid out to the winner. There is no wallet, no stored balance and no interest.

24.18 Where are my items while a round is open?

At launch, in an operator bot account, recorded against that round. They come back to you if you cancel, or go to the winner when the round settles.

24.19 How long do I have to accept a payout?

3 days. If you miss it, or decline the offer by mistake, you have not lost the items: they stay recorded against your win and the payout can be sent again once you have checked your trade URL (section 14.4).

24.20 What happens if Steam goes down during a round?

Offers that are not completed within 90 seconds are cancelled. A round waiting for its deposit is removed with nothing staked, and a round waiting for a joiner's items is reopened. If Steam cannot confirm a cancellation, the round is marked "Trade needs review" and does not flip until support has checked it. A round that has already been decided is not affected; its payout is sent, or sent again, when Steam is back.

24.21 Are item values guaranteed?

No. They are reference values for the game. The operator does not buy items or promise what they could be sold for (section 10.4).

24.22 Can a trade be undone after I confirm it?

RUST50 cannot reverse a trade that Steam has completed. That is why every offer asks only for the items you selected and why you should check it before confirming (section 5.6). If you deposited items into a round you no longer want, cancel the round while it is open to get them back by refund (section 16).

Playing

24.23 Does Black or White have better odds?

No. The side has no effect. Only the stake values decide the chances.

24.24 What are my chances?

Your stake value divided by the pot value. Equal stakes are exactly 50/50. Within the 6% joining range, chances run from about 48.5% to 51.5%.

24.25 Why can a joiner stake slightly less or more?

Exact matches are hard with whole items, so a joiner may stake within 6% of the creator's value. The chances adjust, so a smaller stake simply has a smaller chance.

24.26 What are the stake limits?

A creator stakes USD 1 to 5,000 in item value. A joiner stakes within 6% of the creator's stake, above or below (section 12.3), so a joiner's stake can be roughly USD 0.94 to 5,300. Each side can use up to 25 items.

24.27 Can I play against myself or a friend?

You cannot join your own round, and second accounts are not allowed. You may join a round a friend created, but arranging rounds to pass items to each other is collusion and is not allowed.

24.28 Can I cancel after someone has joined?

No. Once the round is open and nobody is joining, you can cancel it with the "Cancel round" button and your items are returned. While it is still "Preparing items" there is no cancel button: decline the deposit offer in Steam or let it expire after 90 seconds, and the round is removed with nothing staked (section 16).

24.29 What if I close my browser during the flip?

Nothing changes. The result is already fixed, and at launch the payout is sent automatically.

24.30 Where can I see my past rounds?

In "My games" (your latest 50 rounds) and "History" (public results from the last 10 minutes). Each round has its own link, which you can copy with the copy button on the round page, and the Round checker finds any round by number.

24.31 Are there bots playing against me?

In test mode, yes: an automated opponent labelled TEST BOT can join your own round when you choose "Play test bot", and sample rounds opened by test identities are also labelled TEST BOT. Test bots are never real players and never take part in real rounds.

Fees and fairness

24.32 How much is the fee?

Whole items worth as close as possible to, but not more than, 8% of the pot value, with the 8% cap calculated to the nearest cent, taken when the round settles (section 15).

24.33 Why was my fee lower than 8%, or zero?

Items cannot be split. The fee is the best fit of whole items under the 8% limit; if no item fits, it is zero.

24.34 Is the fee taken only from the loser's items?

No. It can come from either player's items, including the winner's.

24.35 Are there any other charges?

No. The house fee is the site's only charge. There is no fee to create, join or cancel a round, and none for deposits, refunds or payouts. Steam does not charge for trade offers. Steam Market fees apply only if you sell items on the Steam Market, and your own internet and device costs are yours.

24.36 What is my expected return?

Between about 92% and 100% of your stake on average, depending on the fee taken (section 15.7). Any single round is a win or a loss.

24.37 Can the operator change a result?

No. The commitment is published before the result, and no administrator, promotion or test control can change a result, the odds, the seeds or a payout. Anyone can check (section 17).

24.38 Does the site know the result before the flip?

Technically, yes: the server holds the server seed, so it can calculate the roll once a round exists. The commitment stops it from changing the seed afterwards, and operator accounts and test bots may not play real rounds (section 17.8).

24.39 Why set my own client seed?

So that one of the values deciding the result comes from you. If you leave it empty, a random one is generated.

24.40 Is the game certified?

Not yet. It must be certified by a testing laboratory approved by the Curaçao Gaming Authority before real play. The Round checker lets you check every result in the meantime.

Safety

24.41 Someone in chat offered me a better deal off-site. Is it real?

No. Staff never make deals in chat or private messages. It is a scam; report it.

24.42 I received a trade offer I did not expect. What should I do?

Decline it. Real offers only arrive right after you create or join a round, or for a payout or refund you are expecting (section 5.6).

24.43 Will RUST50 ever ask me to sign in somewhere else?

No. You sign in only on Steam's own page at steamcommunity.com, reached from rust50.com.

Responsible gambling

24.44 How do I take a break?

Use cooling-off (a time-out) for 24 hours, 7 days, 1 month or 3 months, or self-exclusion for longer (section 21). Until the tools are built, email responsible-gambling@rust50.com; your request is applied on receipt, and at the latest within 24 hours (section 21.4).

24.45 Can I limit how much I stake?

At launch, yes. Deposit and loss limits can be set per day, week or month, and a single-stake limit caps the value of any one stake; session limits and reality checks help you limit your time (section 21.2). Lowering a limit takes effect at once; raising it takes 7 days. Until the tools are built, email responsible-gambling@rust50.com (section 21.4).

24.46 I think I have a problem. What now?

Stop playing, ask for self-exclusion and contact a support organisation (section 21.6). Talking to someone you trust also helps.

Test mode and promotions

24.47 Can I win anything in test mode?

No. Test items have no value, cannot be withdrawn and are not real Steam items.

24.48 Why do I see sample rounds and TEST BOT players?

So that the test lobby has rounds to try. Sample rounds are opened by test identities and show "Sample round" and TEST BOT. They are not real players, and the lobby totals in test mode include them.

24.49 What does the "connected" number next to chat mean?

It is the number of browser connections open to the lobby at that moment. It is not a count of signed-in or verified players: one person with two tabs open counts twice.

24.50 Will my test progress carry over?

No. Test records can be reset at any time, and test identities will not become real accounts. At launch every player signs in with Steam and completes the eligibility checks.

24.51 What is Mazalito?

A planned hourly giveaway that exists only as a test feature, labelled "TEST EVENT". Entry opens for 3 minutes each hour, the prize is one item worth USD 1 to 3, entry needs a qualifying deposit of USD 5, and the winner is drawn at random, with equal chances, from the entrants. In test mode the deposit and prize are simulated and labelled test bots also enter. Test bots will never enter a real draw.

24.52 Are referral rewards paid?

No. The referral programme and the "2.5%" field are inactive and pay nothing (section 19.5).

24.53 Where do I go if my question is not here?

Email support@rust50.com, or see the full list of legal and help documents.