💥 Guide

Chain Reaction Game: Rules, Strategy and Where to Play on iPhone

Chain Reaction is a two-player strategy game with exactly one rule that matters: a full cell bursts. Everything else – the comebacks, the one-move wipeouts, the reason people keep playing it for twenty years – follows from that rule.

The game in sixty seconds

Two players share a grid. On your turn you add one marble to an empty cell or to a cell that already holds your colour. Each cell has a capacity equal to its number of neighbours: 2 in a corner, 3 on an edge, 4 in the middle. The moment a cell reaches that number it bursts: it empties and sends one marble into each neighbouring cell. Any enemy marbles in those cells turn your colour.

If one of those neighbours was itself one marble short, it bursts too. That is the chain reaction – and on a crowded board one tap can turn thirty cells in a single move. The last player with marbles on the board wins. There is no dice, no hidden information and no draw by agreement; the full rules are in Rules.

Why it feels different from Othello or Go

Most capture games move slowly: you win a corner, then an edge, then a region. Chain Reaction stores energy. Every nearly-full cell is a loaded spring, and the player who releases the right spring at the right time collects everything connected to it. Being ahead in marbles is a weak signal – a player with a third of the board can win in one move if the chains line up. That is also what makes the opening matter; see Opening Moves.

Where the game comes from

Versions of the game have existed on home computers since the 1980s, and it spread widely as a mobile game in the 2010s. In German it is known as Kaskade (Kaskade). PlayCascade is a native iOS implementation of the two-player game with an AI opponent, local two-player mode and animated step-by-step cascades so you can actually see what happened.

How to get better

• Take corners first and defend them: they burst at two marbles and can only be reached from two sides.
• Before you fill a cell, count the enemy cells next to it. If one of them is already loaded, your cell will be captured before it ever bursts.
• Build chains deliberately: a line of nearly-full cells that detonates together is worth far more than scattered marbles.
• Against the AI, patience beats aggression – the Expert will punish every loose cell. More in Strategy Tips and Beat the AI.

Playing on iPhone

PlayCascade gives you the game on a 6×6 board for free, with an Easy and Medium AI and pass-and-play for two people on one phone. Pro (one-time purchase) adds the Hard and Expert AI, 8×8 and 8×10 boards and all six themes. The app works offline, shows no ads and has no account. If you have never played, start with Learn in 5 Minutes.