Chansu is a Ruby DSL for working with randomness and probability. It provides helpers like `chance("35%")`, `dice(6, 3)`, and RPG-style aliases such as `d20` and `d100`. It also includes higher-level constructs like `often { ... }`, `rarely { ... }`, and `until_success` for expressive probabilistic logic. Useful for games, simulations, and playful Ruby experiments.