Jutsu Clash is a ninja duel game made and published by Roberto Duran, an independent developer. In this policy, “we” means him. This page explains what the game and its online server keep about you, why, who else handles it, and when it is deleted. It covers the game on every platform (Steam on Windows, Linux and Steam Deck, and later Google Play and the App Store) and this website.
Questions or requests: info@robertoduran.me.
The short version
- Offline play needs no account and sends nothing anywhere.
- The camera never leaves your device. No picture is saved or sent.
- The game's AI runs on your device, for AI rivals and the Forge, and sends nothing anywhere.
- Online play uses a guest account with no email, no password and no real name. The server keeps your ninja's name, level and look, your friends and a few settings.
- No ads, no third-party analytics, no tracking, no chat, no public player lists. We never sell your data.
- You can delete your online account in the game (My Ninja → Settings → Delete my online account) or by email. It is deleted from the server straight away.
- For children and parents
- Playing offline
- The age question
- The hand camera
- AI rivals and the Forge
- Playing online
- Who can see what
- Companies that handle data for us
- What we never do
- How we use what we keep
- Data retention: what is kept, why, and when it is deleted
- Your rights and how to delete your data
- Security
- Changes to this policy
For children and parents
If you are a kid, here is what you need to know:
- You can play against the computer without the internet. Then nothing about you leaves your device.
- The first time you play, the game asks how old you are. It only keeps your age group, never your birthday.
- If you are under 13 and play online, other players see a made-up name for your ninja, like “Swift Crane 42”. The name you type stays on your own device.
- For players under 13, adding friends and challenge alerts are switched off.
- There is no chat, so nobody can send you messages. There are no ads.
- The camera only looks at your hands while you use it. It never takes or sends a picture.
- If something online feels wrong, you can block or report a player, and tell a grown-up.
For parents and guardians:
- We do not ask any player for a name, email, phone number, address, photo or location. The camera's pictures are processed on the device and never collected.
- For a player under 13, the online server keeps only what the game needs to run: a random player id, the generated name, the ninja's level and look, the age group, a few settings and the security data described below. We use it only for the game's internal operations: signing in, running duels, keeping play fair and safe, and protecting the server. We do not use it for advertising or profiling, and we do not share it with anyone except Cloudflare, which runs the server for us.
- No push token is ever created for a player under 13, so Google's alert service is never involved.
- You can ask to see what the server holds about your child, ask us to delete it, or stop any further collection. Use the in-game button (My Ninja → Settings → Delete my online account) or write to info@robertoduran.me. If your child does not open Play Online again, nothing more is sent.
Playing offline
Duels against the AI, the Seal Dojo, the Forge, My Ninja and every other offline mode need no account and no internet. Nothing is sent to us until you open Play Online for the first time.
The game saves your progress on your device: your ninjas, their looks, levels, gear and forged arts, your settings, your answer to the age question and your Seal Dojo samples. This save stays on your device. We cannot see it. You can remove it by retiring a ninja, using Forget my samples, or deleting the game and its data.
The age question
The first time you start the game, it asks one neutral question about your age, with four answers: under 13, 13 to 15, 16 to 17, or 18 and over. Only the age group is kept, never a birth date. The game keeps it on your device. If you play online, the server keeps it with your account, so it can switch on the protections for younger players. Other players never see it.
Players under 13 get these protections online:
- Other players see a generated name (an adjective, an animal and a number) instead of a typed one.
- Adding friends is switched off.
- Challenge alerts are switched off and no push token is created.
The hand camera
In the Seal Dojo and in camera duels, you can form the seals with your real hands in front of a camera. The camera only runs while you use these modes, and only after you turn it on and your system gives permission.
- Recognition happens on your device. No picture or video is saved, and nothing from the camera is sent anywhere.
- To learn your hands, the Dojo keeps the shape of each seal as a small set of numbers (hand-shape measurements, not pictures), for each ninja, on your device. Forget my samples in the Seal Dojo deletes them.
- In online duels, only your seal choices and their timing travel, exactly as with the touch pads or the keyboard.
- You can switch the camera off completely in My Ninja → Settings.
AI rivals and the Forge
The AI rivals you duel and the Forge, where a small neural network writes new special arts, both run on your own device. They work without the internet and send nothing anywhere. If you take a forged art into an online duel, it travels with your duel loadout like any other special (see below).
Playing online
The first time you open Play Online, the game quietly makes a guest account for your device. There is no sign-up, no email and no password. Your device keeps a random secret; the server keeps only a scrambled version of it (a hash) and uses it to sign you in. The server is run on Cloudflare (Workers, Durable Objects and D1).
Here is everything the server keeps:
| What | What it contains | Why |
|---|---|---|
| Account | A random player id, when it was made, your ninja's name, level and look, your age group | Signing in, and showing your ninja to friends and rivals |
| Settings | Who can challenge you, who sees when you are online, whether alerts are on | Doing what you chose |
| Online status | Online, in a duel or offline, and when it last changed | Showing friends whether you can duel (unless you hide it) |
| Device record | A random device id, the hash of the device secret, when the device first and last signed in | Signing in securely |
| Friends | Who you are friends with, and since when | Your friends list and challenges |
| Friend requests | Who asked whom, how (by code), the answer and when | Adding friends |
| Friend codes | Only a hash of the 8-character code, who made it, and when it runs out | Adding a friend in person |
| Challenges | Who challenged whom, the answer, the times, and both players' duel loadouts (ninja name, level, look, main elements, specials, forged arts and gear) | Starting the duel the same way on both devices |
| Duel rooms | While a duel runs: the two loadouts and whether each player wants a rematch. Your moves are passed to your rival, not stored | Running the duel |
| Blocks | Who you blocked, and when | Keeping that player away from you |
| Reports | Who reported whom, a reason from a fixed list (name, cheating, quitting, harassment, other), a short technical note on where it happened, and when. No free text | Safety and fair play |
| Push token (optional, Android) | The address Firebase Cloud Messaging gives your device, and when it was last updated | Challenge alerts while the game is closed, only if you turn them on |
| Rate-limit counters | A count of recent requests, labelled with your player id or your network's IP address | Stopping floods and code guessing |
Like any internet service, the server sees your IP address when your device connects. We use it only for the rate limits above, never to find where you are. Cloudflare also keeps short technical logs of requests to the server so errors can be found and fixed; these can include your IP address and are deleted within 7 days.
Names you type are checked by a filter before anyone else can see them. Today the game does not link your online account to Steam, Google Play Games or Game Center. If that changes, we will update this policy first.
Who can see what
- There are no public player lists and no way to search for players. You only meet players you add in person.
- Someone who types your friend code sees your ninja's name, level and look, and you choose whether to accept them.
- Your friends see your ninja's name, level and look, and whether you are online or in a duel. You can hide your online status and stop challenges in Play Online → Settings.
- A friend you duel receives your duel loadout, so both devices can play the same duel.
- Nobody else ever sees your age group, your settings or your devices.
- There is no chat. Players can't send each other messages.
Companies that handle data for us
We use as few outside services as we can. Each one only acts for us, to run the part of the game named here:
- Cloudflare runs the online server (Cloudflare Workers, Durable Objects and D1). Everything in the table above is stored with Cloudflare. Its servers can be in the United States and other countries.
- Google Firebase Cloud Messaging delivers challenge alerts on Android, only if you are 13 or older and turn alerts on. Google receives your device's push token and the alert itself (for example “Duel challenge! Haru challenges you to a duel”). The game switches off Firebase's analytics.
- Valve (Steam): if you get the game on Steam, Steam handles your Steam account, downloads and any payments under Valve's own privacy policy. We do not receive your payment details.
- Google Play and the App Store, once the game is there, do the same for their versions under Google's and Apple's own policies.
There are no in-game purchases. The only payment is for the game itself, and the store you buy it from handles it.
What we never do
- No ads, and no advertising or analytics code from other companies in the game.
- No tracking across apps or websites, and no advertising ids.
- No location, contacts, microphone or photos.
- No selling or renting of your data, and no sharing it for advertising.
- No profiling, and no decisions about you made automatically from your data.
- This website uses no cookies, no analytics and no trackers. It is hosted on Cloudflare, which sees your IP address when you visit, as any web host does.
How we use what we keep
We use the data above only for the game's internal operations:
- signing you in and keeping your guest account;
- showing your ninja to your friends, and running friend codes, requests and challenges;
- running online duels so both devices play out the same duel;
- sending challenge alerts, if you turned them on;
- looking into reports, and suspending accounts that cheat or harass;
- protecting the server from floods, guessing and attacks, and fixing errors.
If you are in the European Union or the United Kingdom: we use this data because it is needed to give you the online play you ask for, and, for safety reports, rate limits and error logs, because of our legitimate interest in keeping the game safe and working.
Data retention: what is kept, why, and when it is deleted
We keep data only as long as it is needed for the reasons above. A clean-up runs on the server every day and deletes whatever has run out. Nothing is kept forever: when you delete your online account, everything in it goes at once.
| What | Why we keep it | When it is deleted |
|---|---|---|
| Account, settings, online status, age group | So you can keep playing online | When you delete your online account |
| Device records | Signing in | When you delete your online account |
| Friends | Your friends list | When either of you unfriends or blocks the other, or deletes their account |
| Friend requests | Waiting for an answer | 14 days after they were sent, answered or not |
| Friend codes | Letting a friend add you | A code works once, for 10 minutes. Its hash is deleted at the next daily clean-up, or as soon as you make a new code |
| Challenges and the duel loadouts in them | Starting the duel | 7 days after the challenge was sent |
| Duel rooms | Running the duel | When the duel ends, or 45 seconds after a challenge is accepted if nobody joins |
| Blocks | Keeping a player away from you | When you unblock, or either account is deleted |
| Reports | Looking into cheating and abuse | 12 months after they were made, or sooner if either account is deleted |
| Push token | Challenge alerts | When you turn alerts off, when Google says it no longer works, after 30 days without an update, or when you delete your account |
| Rate-limit counters (with an IP address or player id) | Stopping floods and guessing | Each counter covers 10 minutes to a day, and is deleted at the first daily clean-up after that, so within two days |
| Cloudflare's technical logs | Finding and fixing errors | Within 7 days |
| Your save, age answer and Dojo samples on your device | Playing the game | Stay on your device until you delete them (Forget my samples, retiring a ninja, or deleting the game's data) |
| Emails you send us | Answering you | Deleted once your question or request is dealt with, unless we need to keep a short note that a deletion request was done |
Your rights and how to delete your data
Wherever you live, you can ask us to show you what the server holds about you, give you a copy, correct it, delete it, or stop using it. Write to info@robertoduran.me and we will answer within 30 days. Because the guest account has no email or password, we may ask a question or two to make sure the account is yours.
To delete your online account, use the button in the game, My Ninja → Settings → Delete my online account, or email us. The delete account page explains exactly what is removed and when.
If you are in the EU or the UK and think we have not handled your data properly, you can also complain to your data protection authority. We would like the chance to put it right first.
Security
- The game talks to the server only over encrypted connections (HTTPS and secure WebSockets).
- The device secret and friend codes are stored only as hashes, never as they are.
- Sign-in sessions last 24 hours, and requests are rate-limited.
- The server checks everything a player sends before anyone else sees it, and only the two players in a challenge can see it.
No system is perfect. If we ever learn of a breach that affects you, we will tell you and the authorities as the law requires.
Changes to this policy
When the game changes what it keeps, we update this page and its effective date before the change goes live. If a change needs your consent, or a parent's, we will ask for it in the game first.
Contact
Roberto Duran, publisher of Jutsu Clash: info@robertoduran.me