About ProStriker

A schoolyard game, rebuilt so you can play it against someone on the other side of the world at two in the morning.

Last updated: 2026-08-23

What this is

ProStriker is a free implementation of paper football — the pen-and-paper game played on the grid of a squared notebook. It runs in a browser, installs as an app if you want it to, and exists as an Android application.

Three ways to play: against a bot with three difficulty levels plus an adaptive Auto mode, against somebody sharing your screen, or online against another person by room code or random matchmaking. The first two work with no internet connection at all.

The interface is available in English, Polish, German and Spanish. The rules are the standard ones: an 8 × 10 pitch, goals two squares wide, bounces off occupied dots and off the wall, and a loss for whoever runs out of moves.

Why it exists

Paper football is played by a lot of people and served badly by software. The implementations that exist tend to be either abandoned, buried in advertising, or built on some interpretation of the rules that does not match how anybody actually plays.

The specific gap was online play. Playing a bot is fine practice; playing the person next to you is the real game. But the person next to you is not always there, and there was no straightforward way to sit down and play a stranger a proper game of paper football with the standard rules.

How it is built

Deliberately plainly. The game is HTML, CSS and JavaScript with no framework and no build step — the file the browser downloads is the file in the repository. It loads quickly on a bad connection and it will still run in five years.

The rules engine is a single shared file used in three places: your browser, the Android app, and the multiplayer server. That is what makes the server authoritative without the two sides ever disagreeing about what is legal — there is only one implementation of the rules.

The Android app is the same web game in a native wrapper, so a fix ships to both at once. The multiplayer server is Node.js with a PostgreSQL database behind it, running on a single machine in Germany.

Free, paid, and advertising

The game is free and the whole of it is playable without paying: every mode, online play included, and the ranking. There is no energy meter, no timer and nothing locked behind a purchase.

It is funded two ways. The Android app shows advertising. There is also an optional premium account which removes the ads and supports the project; it changes nothing about the game itself, because a paper football game where money buys an advantage would be a worse game.

This website carries advertising on its content pages, such as this guide. It is not shown on the game screen — partly because it would be intrusive, and partly because advertising belongs next to things people are reading.

Who is behind it

ProStriker is run by Kynologic Sp. z o.o., a company registered in Poznań, Poland. The full company details, registration numbers and a contact address are on the contact page.

The project is independent and small. Bug reports, rule disputes and feature ideas all go to the same inbox and are read by someone who plays the game.

What comes next

The near-term work is the parts of the ranking that are visible: proper leaderboards on the site, weekly and monthly tables, and tournaments that run on a schedule rather than on demand.

Beyond that, the list is the usual one — a stronger bot, saved replays, more languages. It is a small project without a roadmap document, and the things that get built first tend to be the things people write in about.

Frequently asked questions