Terms of use

Last updated 28 September 2026

These are the rules for using Open Mercy. They are short because the game is simple: it is free, it asks almost nothing of you, and it asks that you do not ruin it for anyone else. By playing, you agree to them.

On this page

What Open Mercy is

Open Mercy is a free card game you play in a web browser, solo against bots or online with other people. It is an independent project built and run by one developer, alii13. There is nothing to buy inside the game.

Accounts

When you press PLAY NOW you get an anonymous guest account: a random id and a made-up handle. You can play everything with it. If you want to keep your stats, you can claim the account with an email address or a Google sign-in.

You are responsible for what happens under your account. If you share a device, remember that anyone using that browser can play as you. Guest accounts live in your browser, so clearing its data can lose one for good. A claimed account can be signed back into.

Fair play

Play the game as it is meant to be played. In particular, do not:

Found a bug that gives you an edge? Please report it. That is always welcome.

Names and voice chat

Your display name is seen by everyone you play with and can appear on public leaderboards. Do not pick a name that is hateful, sexually explicit, harassing, or that pretends to be another person.

Voice chat is optional and only works in online rooms. It is live audio between the players in that room. It is not recorded by Open Mercy and nobody moderates it as it happens, so the same rules apply: no harassment, no hate, and nothing you would not say to a stranger's face. If someone makes voice chat unpleasant, you can leave it and keep playing.

What happens if you break the rules

Depending on what happened, a name can be changed or removed, results and leaderboard positions can be reset, and an account can be blocked from playing online. This is a judgement call made by the developer, not an automated process, and there is no formal appeal. If you think a decision was wrong, say so through the contact page.

Availability

The game is provided as it is, when it is up. Features can change or be removed, rules can be adjusted, and the service could be paused or shut down. Empty online rooms are removed automatically after a while. Stats and leaderboards are kept in good faith but are not guaranteed to last forever.

Trademarks and code

UNO® and UNO Show 'Em No Mercy® are trademarks of Mattel, Inc. Open Mercy is not affiliated with, sponsored by, or endorsed by Mattel.

The Open Mercy source code is published on GitHub under the MIT license, which sets out what you may do with it. Music and sound effects come from third parties under their own licenses, credited in the game's footer.

Ads, analytics and privacy

The site uses analytics to understand how the game is played and may show ads to cover running costs. What is collected, and by whom, is described in the privacy policy. That page is part of these terms.

No warranty

Open Mercy is free and comes with no warranty of any kind. It may have bugs, lose a game in progress, or be unavailable when you want to play. To the extent the law allows, the developer is not liable for any loss or damage that comes from using it, or from not being able to use it.

Changes to these terms

These terms may be updated as the game changes. The date at the top shows the latest version. If you keep playing after a change, the new version applies.

Contact

Questions about these terms go through the contact page.