Maze Rats is an RPG and sandbox toolkit for old-school-style adventuring. It contains a single, compact page of rules, a one-page character creation guide, a hand-drawn character sheet, and eight pages of random tables'
... Maze Rats offers everything you need in a compact, easily-referenced format. Also included is two pages of advice for preparing and running open-world games in the OSR style.
The game uses a simple 2d6 system for action resolution.