Flipside

Flipside is Ethan Mollick's seeded coin-flipping roguelike, built around a scoring rule that makes both outcomes useful. Heads contribute Chips, tails contribute Mult, and each toss scores the product of those two totals. The complete pattern adds another layer: all heads forms Midas, all tails forms Nocturne, alternating results form Pendulum, and palindromic sequences form Mirror. A limited shared supply of reflips turns a nearly completed pattern into a decision between chasing a stronger result and preserving resources.

A run spans eight antes, with four tosses available to beat each target. Between bets, earned currency buys passive Charms, enchanted coin materials, one-use Fortunes, and Omens that improve pattern levels. Every third bet introduces a boss rule that disrupts familiar plans. The broader progression includes six starting pouches, four stake tiers, five fixed challenge setups, daily shared seeds, endless play, relics, skip tags, and a persistent profile. The game, generated soundtrack, and art are original to the project, while the engine is tested through headless simulations and action fuzzing. Its single HTML source is MIT licensed.

Start a run and choose up to five coins for a toss. Resolve the flip, then read the Chips, Mult, and named pattern produced by the result. Spend a reflip on an individual coin when changing one face could complete a valuable pattern, or keep the current result and preserve the shared reflip pool for a later toss. You have four tosses to reach the displayed target for the bet.

After winning, use the shop to shape a build. Charms create passive scoring engines, coin materials alter individual coins, Fortunes provide single-use effects, and Omens raise the value of recurring patterns. Plan purchases around the current pouch instead of treating every upgrade as equally useful. Watch for the special constraint on every third boss bet and adapt before tossing. Across later runs, experiment with unlocked pouches and stake levels, or use challenge and daily modes when you want a fixed setup or shared seed.