In Corrosion, each of you manages a factory and deploys engineers to build up diversified scoring and production engines. In the steam-filled air, however, your biggest enemy is time because most machines and gears rust away quickly, so you are well advised to also produce chrome gears and invest in rustproof and powerful chrome machines.
On your turn, you can either play an engineer card or turn the corrosion wheel of your factory:
Playing engineers mostly gains you new machines and qualified engineers. Other players can copy your engineer's action by playing an engineer of the same suit but a higher grade. Turning your corrosion wheel puts your machines to work and returns engineers to your hand, but also causes old gears and machines to rust. To be successful, you must cleverly co-ordinate your engineers and corrosion wheel and smoothly shift from one efficient engine to the next.
The game end is triggered once the special point supply or the award supply run out. Then, whoever was able to score the most points with their machines and awards wins.