Mathematics

Although almost any roguelike uses numbers somewhere (for example, to keep the number of hit points, or to calculate the damage caused by your +N sword), there are some roguelikes which use Mathematics in a more artistic way, as a theme rather than a tool. Some of them include a gameplay concept based on something which was invented by mathematicians. Most of these are 7DRLs. These include:

• MathRL, an abstract seven-day roguelike where your weapons are mathematical functions, and you have to combine them in a way which produces the largest output.
• Numbers, a seven-day roguelike, whose goal is to teach the players how to count.
• Decimation, a simple seven-day roguelike where you are paying a 0 wanting to annihilate all other numbers.
• Hydra Slayer, where you will need to calculate the effects of your attacks in order to be successful, and number-theoretical properties of the number of heads on a given hydra count, like divisibility. Also some weapons and many of the dungeons come from a mathematical theme.
• Hyperbolic Rogue, another seven-day roguelike which contains no numbers (other than your score etc), but the world is a hyperbolic plane.

Mathematical themes can be also found in other roguelikes, like:

• In ADOM, the rules of how herbs grow are based on Conway's Game of Life.
• KleinRL is a roguelike played on a Klein bottle.