Terms of use

Private test version. Last updated 15 November 2026. Before public release the operator's name and postal address will replace the placeholders below.

1. Who we are and how to contact us

ChesStresS is run by Kajetan Kupka, a private individual in the United Kingdom (not a company), [POSTAL ADDRESS] ("we", "us"). Contact and support: [email protected]. Messages are answered with the help of an AI assistant; decisions on bans, appeals, refunds and data requests are made by a person.

These terms are a contract between you and us when you use ChesStresS on the web or in the app. Please also read the Privacy policy and Safety & reporting.

2. The game

ChesStresS is a chess game. You can play against the computer, solve puzzles, take lessons, review games, and play online against other people, in tournaments, in Turbo Live (team voting) and in Four Stressed and Wild Stressed (chess for four, and chess with two extra pieces for two or four; unrated and without tokens). This is a private test version: features may change, the service may be unavailable at times, and progress, ratings and token balances may be reset before public release.

3. Who can play

You must be 13 or older. If you are under 18, please play with the agreement of a parent or guardian, who should read these terms with you. Purchases by under-18s need a parent or guardian, through the App Store or Google Play family settings. If we learn that an account belongs to someone under 13, we close it and delete it 7 days later (Safety & reporting).

Online play (games against other people, tournaments, Turbo Live and creating an account) is available only in the countries we have opened it in: at present the United Kingdom, Australia, New Zealand and Poland. Games against the computer, puzzles and the school work everywhere, and you can see and delete your account data from anywhere.

4. Accounts

You can play as a guest without an account. Rated games, tournaments, rated Turbo Live events and Turbo top-ups need a free account. Guests can play free Turbo Live events and can watch tournaments and rated events.
When you create an account you confirm that you are 13 or older and that you accept these terms. Our server records that confirmation, the version of the terms and the time. To stop accounts being created in bulk, the number of new accounts from one network in 24 hours is limited.
An account has a nickname (Latin letters, digits, spaces and the signs _ . - only; a name that is the same as, or looks like, one already taken is refused), a secret key stored on your device and a recovery code shown once. Keep the recovery code safe: we do not know your email address and cannot restore an account without it. Anyone with your recovery code can take over your account.
One account per person. Do not share, sell or transfer accounts.
You can delete your account at any time in the Account tab (see Delete your account).
An account that is not used for 24 months is deleted, with its tokens and ratings. If you open the game in the last 30 days before that, the app tells you and the account is kept.

5. Tokens

Tokens are a game item with no cash value. They cannot be exchanged for money, goods or real-world prizes, cannot be withdrawn, sold or transferred between players, and are never paid out in money. You can always play without spending tokens: casual and rated games, friendly and correspondence games, free tournaments, Turbo practice and free Turbo Live events cost nothing, and free tokens can be claimed every 4 hours.

A new account starts with 500 tokens. A guest's tokens are kept only on the guest's device; they are not moved to an account and are lost if the device's data is cleared.
Earned and bought tokens. An account's balance has two parts, shown separately in the Account tab. Earned tokens are the starting grant, free tokens, prizes and refunds of fees paid with earned tokens. Bought tokens are tokens bought under section 6 (nothing can be bought yet). Tournament entry fees, Turbo Live top-ups and the fees of computer rooms can be paid only with earned tokens, so bought tokens never go into a prize. Boards and Turbo Live entry fees (Turbo Live pays no prizes) can be paid with both: bought tokens are used first, then earned tokens. A refund goes back to the part it was paid from. Every change in the token history shows which part it came from.
Tournaments. Tournaments are for accounts; guests can watch. A tournament created by a player is always free: it has no entry fee and pays no tokens. Only official tournaments (the ones our server opens) can ask for an entry fee in earned tokens, and they pay prizes in tokens only. A tournament with an entry fee is played only if at least 4 different accounts have entered; otherwise it is cancelled and every fee is refunded. Results depend on chess skill, not on chance. A fee is refunded if you leave before the tournament starts or if it is cancelled. The prizes are exactly the fees collected – nothing is added and nothing is kept back – and go to the top three places only (4 players: the winner takes all; 5–8: 65% and 35%; 9 or more: 50%, 30% and 20%). Prizes are earned tokens. Family accounts (accounts with unlimited tokens used by the operator's family and for testing) and the operator's own (admin) account never receive prizes; a prize such an account would have won goes to the next eligible player.
Turbo Live. There are two kinds of event. Free events cost nothing, are open to guests and are unrated. A game in which a team plays against the engine (Stockfish), because the other team has nobody online, is practice: the game says so on the screen, and it gives no points, no badges and no TSR. Rated events have an entry fee in tokens, shown before you enter and confirmed by you (at the moment 30, 50, 70 or 120 tokens for 5, 10, 15 or 30 minutes, and 150 tokens a week for the Weekly Marathon); it can be paid with earned or bought tokens (bought tokens first) and buys a place in the event only. The entry fee is refunded if the event is cancelled (a rated event that has not started 30 minutes after the first entry is cancelled), if you withdraw before your first game, or if the event ends without you ever having been placed in a game. Family accounts enter without paying. If your agreement with your team falls below the line, you can stay in by paying a top-up from earned tokens only (up to 3 per event; each one costs more than the last). The time to decide on a top-up is a rule of the game; tokens cannot be bought during an event (the Get tokens screen is closed while you play in one), and without enough earned tokens your only choice is to drop out. Turbo Live pays no token prizes and no other prizes. What you play for is your TSR (Turbo StresS Rating), your place in the standings and ladders (the Weekly Marathon ladder and the TSR leaderboard are public) and badges, for example “Marathon Top 10 — week 46, 2026”. Badges are shown on your profile; they are for show only, have no value, cannot be traded or transferred and cannot be exchanged for tokens. How TSR and CSR (ChesStresS Rating) are calculated: How ratings work.
Turbo practice (your team-mates and opponents are simulated, Stockfish runs on your device). Turbo practice is free for everyone, guests and accounts: there is no entry stake, no top-up cost and no token prize. If your agreement falls below the line, you can continue for free up to 3 times per event, or drop out. You play for points, your place in the standings and experience points (XP), which have no cash value and cannot be exchanged for tokens. Token changes made before Turbo practice became free stay in your token history.
Games against the computer. With an account, the room's entry fee is taken from your earned tokens by our server when the game starts, and the prize is paid by our server when the result is reported, once per game: a win pays twice the fee (20 tokens in the free School room), a draw returns the fee, a loss pays nothing. A win is paid only when the game sends the record of the game and our server, replaying the moves by its own rules, finds a legal game that ends with your checkmate. A win the server cannot confirm in this way (for example a win on time) is settled like a draw: the fee is returned and no prize is paid. Because these games run on your device, winnings above what you paid in are limited to 3,000 tokens and to 20 paid wins in any 24 hours; after that a win returns the fee only. A game left unfinished when you start another one counts as lost, and a result reported more than 12 hours after the start pays nothing. Family accounts are not charged and not paid. Guests keep their tokens on their device only.
Boards. A board is free once you reach its level, or you can buy it earlier with tokens. With an account the price is set and charged by our server and the board stays with your account (family accounts have every board); your level is worked out on your device. Guests cannot buy boards.
Avatars. The basic avatars are free. Premium (animated) avatars are part of the Max membership (section 6) and are shown while the membership lasts; they are not sold for tokens. An animated avatar bought with tokens before 14 November 2026 stays with its account. Some avatars can only be earned (for example by winning the Weekly Marathon) and are never sold. Avatars are cosmetic only: they have no value, give no advantage and cannot be traded or transferred.
Every token change of an account is listed in its token history in the Account tab.
We may correct token balances that result from a mistake, a bug or a breach of these terms, and we will tell you if we do.

6. Purchases

Nothing can be bought in ChesStresS at the moment. On the website the "Get tokens" screen (Profile › Get tokens) shows the planned token packs with their price in pounds, the number of tokens and the price per 100 tokens; its Buy buttons read "Coming soon". In the apps from the App Store and Google Play the token packs, the memberships and their prices are not shown at all until they can be bought there. When purchases are added, these rules will apply, and we will update these terms before they go live:

Purchases are made only through Apple's App Store or Google Play, using their payment systems, under their terms. We never see your card details. You need an account to buy.
Before you pay you will see the item, what it does, and its full price in your local currency. Wherever tokens can be spent on a board, we show their approximate value in pounds next to the token price, based on the price per token of the cheapest pack; things that can be paid only with earned tokens say so.
Bought tokens can be spent on boards and Turbo Live entry fees (Turbo Live pays no prizes). They cannot pay tournament entry fees, Turbo Live top-ups or computer-room fees, and never go into a prize (section 5).
Bought tokens do not expire. An account that still holds bought tokens is not deleted for not being used. Bought tokens have no cash value and otherwise follow section 5; if you delete your account they are lost.
Money never buys an advantage on the board. There are no paid random rewards ("loot boxes").
Spending controls, already in place (Profile › Account › Spending controls): a monthly spending limit in pounds that you choose, from £0 to £1,000 or no limit (lowering it takes effect at once; raising or removing it takes effect 24 hours after you ask); a purchase pause for 24 hours, 7 days, 30 days or 6 months, which cannot be lifted or shortened, only extended; and a purchase history. Every purchase is checked against your pause and your limit (counted per calendar month, UTC) before it can go ahead. These settings are deleted with your account.

Your right to cancel. If you are a consumer in the UK or the EU you normally have 14 days to cancel a purchase of digital content. Tokens are added to your account straight away. Before you pay you must tick this box: "I want my tokens now. I understand that once they are added to my account I lose my right to cancel this purchase within 14 days." If you do not tick it, the purchase does not go ahead. We keep the time you ticked it with the purchase record, and the purchase appears in your purchase history; the store also sends you its receipt. This does not affect your rights if an item is faulty or not as described: under the Consumer Rights Act 2015 you can ask for it to be repaired or replaced, or for a price reduction or refund. Refunds are handled through Apple or Google; contact us first and we will help.

Memberships (subscriptions): not on sale yet. Three memberships are planned: Plus (£2.99 a month or £24.99 a year), Pro (£5.99 or £49.99) and Max (£9.99 or £84.99). The prices include VAT and may change before the sale starts; the price you pay is always shown before you confirm. During the test and the first months everything is open to everyone free of charge and nothing below is charged. When memberships go on sale these rules apply:

What you get. Tools, access and looks only: unlimited game review and puzzles, all boards and saving up to 10 games in one PGN file (Plus); also entry to rated Turbo Live events and the Weekly Marathon without a fee, creating tournaments and Turbo Live events, statistics and saving up to 50 games in one PGN file with your engine analysis (Pro); also animated avatars, saving every game you have played in one PGN file with your engine analysis, deep analysis on our server, creating four-player online tables in Four Stressed and Wild Stressed and a family plan (Max). A membership never gives rating points, prizes or any advantage on the board. Free accounts can always play people and the computer, use the school and free events, and get 1 new game review and 10 new puzzles a day. Saving the record (PGN) of a single game is always free.
How you pay. Only through Apple's App Store or Google Play, monthly or yearly, in advance. You need an account. We never see your card details.
It renews automatically at the end of each month or year, at the price then shown in your store account, until you cancel.
Free trial. Pro starts with 7 days free, once per person. If you do not cancel before the trial ends, the first payment is taken and the membership continues.
Cancelling is easy and can be done at any time: in the app under Profile › Memberships › Manage (it opens your App Store or Google Play subscriptions page), or directly in your store account. You keep the membership until the end of the period you have paid for; it then stops and nothing more is charged.
Your right to change your mind. You can cancel within 14 days of first subscribing, and within 14 days after a free trial turns into a paid membership or a yearly membership renews, and get your money back (for a period you have already used, a fair part may be kept where the law allows it). Refunds are paid through Apple or Google; write to us and we will help.
Reminders. Before a free trial ends, before a yearly membership renews and every six months for a monthly membership, you get a notice in the app (Profile › Account › Notices) with the date, the amount and how to cancel, in addition to the emails Apple or Google send you. We do not have your email address.
When a membership ends the boards and avatars it lent you are locked again unless your level or a token purchase unlocked them; the daily limits of free accounts apply; your ratings, games, tokens and anything bought with tokens stay as they are.
Price changes are announced in advance by the store and in the app, and you can cancel before a new price applies.
Under 18. A membership needs a parent or guardian, through the App Store or Google Play family settings (Ask to Buy, Family Link).
If you live in the European Union. You have 14 days to withdraw from a membership without giving a reason. You can do it in the app with the button “Withdraw from contract here” (Profile › Memberships), which confirms your withdrawal on screen and in your Notices, or by writing to us; you do not have to use any particular form. The mandatory consumer law of your country applies as well as these terms.

These rules follow the Consumer Contracts Regulations 2013 and the subscription rules of the Digital Markets, Competition and Consumers Act 2024 (in force from 1 January 2027) in the United Kingdom, and the Consumer Rights Directive 2011/83/EU, including its withdrawal function (Article 11a), in the European Union. They do not limit any right the law gives you.

7. Fair play

Play your own moves. Chess engines, opening or endgame databases during live games, and help from other people are not allowed. In correspondence games opening books are allowed; engines are not.
Do not lose on purpose, agree results in advance, use several accounts, or play from someone else's account.
Computer opponents are always labelled as such. Online games are against people, with two exceptions that are always shown: in Turbo Live a team may play against Stockfish when the other team has nobody online (such a game is practice and gives no points, badges or TSR), and at Four Stressed and Wild Stressed tables empty seats can be taken by computer players.
We keep the moves, move times and simple statistics of online games, and the app counts how often it was in the background during your own moves (see the Privacy policy). From these the server can raise a flag for a person to look at. A flag changes nothing for you. Nothing is decided automatically: a person reviews every flag and report and the evidence before any action.
One account per person. Do not use other accounts to raise or lower a rating, to win tournaments or to get round a restriction.
Leaving games (a game rule). A live game you lose on time while you are not connected counts as abandoned. After 3 abandoned live games within 24 hours, rated pairing (rated quick games, rated challenges and rated rematches) is paused for 10 minutes from the last of them, and the app tells you why and until when. Casual games stay open. This rule is the same for everyone, is applied by the game itself and is not a penalty or a finding that you did anything wrong: it only keeps players who are having connection trouble, or a bad day, from leaving more opponents waiting. It does not appear in your Notices and needs no appeal; if you think it was applied in error, tell us.
Limits that keep the game pleasant (game rules). You can offer a draw at most 3 times in a game, and after an offer was not accepted you can offer again 5 moves later. You can ask for a rematch once per game; a declined rematch cannot be asked for again. Challenges that are not accepted are limited to 3 to the same player and 20 in total per hour.

8. Behaviour and your content

Your nickname must not be offensive, sexual, hateful, threatening, impersonate someone (including staff, FIDE or other organisations), contain contact details or advertise anything. Only Latin letters (with accents), digits, spaces and the signs _ . - can be used. Nicknames are filtered, but the filter is not perfect.
Zero tolerance for insults, swearing and harassment. No harassment, threats, bullying, hate, sexual remarks, insults or swearing, in any language, in a nickname or by any other means (including repeated unwanted challenges, rematch or draw requests, deliberately stalling a lost game, or using the preset phrases to mock someone). No cheating, spamming, or attempts to break, overload or reverse-engineer the server. Do not use bots or automated tools against the server.
Chat in games is limited to preset phrases and, at four-player tables, preset reactions. You can report or block a player wherever you meet one, including at four-player tables (Safety & reporting). You can mute an opponent's chat during a game or switch chat off altogether (Profile › Settings). Do not use the game to share or arrange anything illegal.
Reports must be honest. Repeated false or malicious reports are a breach of these terms.
Your games. You and your opponent may freely use, record, stream and share your own games, including screenshots and video. You allow us to store your games and to show and broadcast them inside ChesStresS and on its official channels under your nickname. You may not copy other players' games in bulk or by automated means.

9. What we can do if the rules are broken

If a person reviewing a report or a flag finds that you broke these terms, we choose the lightest measure that fits what happened (the ladder of consequences):

Warning: a notice in the app; nothing is restricted.
Restriction, for a set number of days or until lifted: no rated play (rated quick games, rated challenges and tournaments; casual games stay open); or no tournaments and no rated Turbo Live events; or chat switched off (you cannot send preset phrases).
Forced rename: a nickname that breaks section 8 is reset to “Player-xxxx” and you choose a new one.
Account closure, for fair-play violations (cheating, boosting, collusion, multiple accounts) or for abuse (harassment, hate, threats, serious or repeated insults). A closed account cannot sign in. It is deleted 12 months after the closure, or sooner if you delete it.

When an account is closed or marked for cheating it is removed from the leaderboards and ladders, its badges are removed, and opponents who lost CSR points to it in rated games in the previous 90 days get those points back (they see a notice). Tokens are not taken from anyone automatically; a tournament prize won unfairly may be cancelled by the operator after review. Serious cases can go straight to closure. We act in proportion to what happened. If there is a serious risk to someone's safety, or the law requires it, we may act first and review straight after. We tell you the decision and the reason in the app (Account tab, "Notices", with the date and how to appeal) or, if you emailed us, by email, unless the law or someone's safety prevents it.

Appeals. You can appeal within 30 days by emailing [email protected] with your nickname and anything you want us to consider. A person looks at the case again and replies, normally within 14 days. If the appeal succeeds, everything the decision changed is put back: the restriction or closure is lifted, a reset nickname and removed badges are restored where possible, and rating corrections made because of it are reversed. See Safety & reporting.

10. Changes and ending

We may change the game, these terms or the rules for tokens, for example to add features or to follow the law. For changes that matter to you we will show a notice in the game in advance. If you do not agree, you can stop playing and delete your account.
You can stop using ChesStresS and delete your account at any time.
If we close ChesStresS we will tell you at least 60 days in advance in the game, and stop selling anything as soon as we announce the closure. Your consumer rights for anything you paid for are not affected.

11. Software and licences

The game uses Stockfish, a chess engine licensed under the GNU General Public License version 3. The ChesStresS client that runs on your device is free software under the GPLv3; these terms do not limit your rights under that licence. The name "ChesStresS", the logo and the visual identity are not licensed under the GPL. The server is a separate service. Details: About & credits.

If you downloaded the app from Apple's App Store, Apple's Licensed Application End User License Agreement also applies. Apple and Google are not responsible for the game, its content or its support.

12. Our responsibility to you

We provide the game with reasonable care and skill. As a consumer you have legal rights, including under the Consumer Rights Act 2015, for digital content that is faulty, not as described or not fit for purpose. Nothing in these terms affects those rights.
If digital content we supply damages your device or other digital content because we did not use reasonable care and skill, we will repair the damage or pay you fair compensation.
We do not limit or exclude our liability for death or personal injury caused by our negligence, for fraud, or for anything else the law does not allow us to limit or exclude.
Otherwise we are not responsible for loss that was not foreseeable when you started using the game, or for business losses: ChesStresS is for personal entertainment only.
The free game, and especially this private test, may sometimes be unavailable or lose data. Keep your recovery code safe.

13. Complaints and law

If you have a complaint, email [email protected]. We will reply within 14 days.

These terms are governed by the law of England and Wales, and the courts of England and Wales can hear disputes. If you live in Scotland or Northern Ireland you can also bring proceedings in your home courts. If you live in the European Union, you keep the protection of the mandatory consumer laws of your country and can bring proceedings in your country. For consumers who live in Poland the Polish version of these terms applies. If you live in Australia or New Zealand, nothing in these terms excludes, restricts or changes any right or remedy you have under the Australian Consumer Law, or under the New Zealand Consumer Guarantees Act 1993 and Fair Trading Act 1986, that cannot lawfully be excluded, and you can bring proceedings in your home courts.