Cookies
Last updated: 9 October 2026
15-0 uses what it needs to work (one cookie to keep you signed in if you sign in with Google, and a few preferences kept in your browser) and, only if you accept them, Google’s cookies for the ads you choose to watch for extra re-rolls and for analytics (Google Analytics). That is why we show you Google’s consent message when you arrive.
1. Cookies
The first two are technical and necessary, set by 15-0 itself, and only exist if you sign in with Google.
| Name | Purpose | Lifetime |
|---|---|---|
s13 | Keeps you signed in, signed so nobody can forge it. HttpOnly, SameSite=Lax, Secure. | 180 days, or until you sign out |
o13 | Protects the round trip to Google when you sign in (a one-time code). Only sent to /api/auth. | 10 minutes, deleted on return |
_ga, _ga_* | Google Analytics: tells visits and sessions apart to count how many people visit and how much they play. Only if you accept analytics in the message; on its domain and under its policy. | 13 months |
2. Browser storage
15-0 also keeps in your browser (local storage, which is not sent to any server by itself):
| Key | Purpose |
|---|---|
d13-nick | Your nickname in rooms and challenges. |
d13-team | The name you give your team. |
d13-fmt | The format you chose (modern or classic). |
d13-view | Whether you follow the matches live or as a summary. |
d13-seat | A random identifier to recognise you if you come back to a room. |
d13-trophies | Your trophies and when you earned them. |
d13-pending | A finished game waiting to be published while you sign in with Google. |
3. Third parties
If you sign in with Google, the Google page where you choose your account uses its own cookies, on its own domain and under its own policy. The fonts are served by 15-0 itself, not through Google.
The ads are served by Google AdSense. If you accept them in the consent message, Google and its partners use advertising cookies, on their own domains, to serve ads based on your visits to 15-0 and other sites, and to measure them; if you do not, the ads you see will not be personalised. Which cookies Google uses and why is on its advertising page. You can opt out of personalised advertising in Google’s Ads Settings or at www.aboutads.info.
Analytics is Google Analytics. With your consent in the same message it uses its cookies to count visits and sessions; without it, it keeps no cookies or identifiers.
4. Managing them
Signing out deletes the session cookie. You can change or withdraw your consent to the ads at any time with “Manage cookies” at the foot of the page. You can also clear the site’s cookies and storage in your browser settings: you will be signed out and this browser’s language, nickname and trophies will start empty (your account’s trophies come back when you sign in).
5. Changes
If we ever add other cookies, this page will say so before they are switched on, and we will ask for your consent with the message.