The objective is to see if a little input energy can be continued through a system in either a single event or a variety of ways. Users build sequences of events such that one action triggers another action which triggers another action and so on. Falling dominoes are a basic form of this. Rube Goldberg inventions are the most intricate. There are multiple beginning and end points for chain reactions; each depends on the actions of the individual builders, and all are made meaningful by what happens in the middle, especially the process of building and problem solving. Users are invited to try out an idea; build toward it, test it, redesign, build and test again. And again. Things fall apart. Things fall over. Working with My Chain Reaction often means figuring out how to make something do what you want it to do through multiple attempts and arrangements, or thinking of ways to use a specific item to continue a sequence of action.