KUBBU started as a small collection of math mini-games and is evolving into a platform for exploring deeper ideas: strategy, invariants, and why a method works (not just the final answer).
The story behind KUBBU and its growing collection of browser-based puzzle games.
KUBBU is designed and built by Ryan Cai. The first set of games focused on fluency (arithmetic, fractions, algebra). The next step adds proof-flavored games where the goal is to discover structure—like an invariant or a winning strategy. Some games on this site are inspired by competition-style mathematics.