Chained Combo Strings

Hit reaction is the mechanism. A connecting attack puts the target in a stun state lasting a fixed number of frames, and an attack begun inside that window arrives before the defender regains control. Chaining therefore depends on frame data rather than on any dedicated combo mode, and skill lies in knowing which moves recover fast enough to link, which is why the technique produced deep, memorised notation among competitive players.

Capcom did not design it. While finishing Street Fighter II: The World Warrior in 1991 the team noticed that cancelling the recovery of one move into another let hits connect in sequence, judged the timing too demanding for most players to exploit, and left it alone. Players found it within weeks. Combos consequently arrived as a discovered property of the engine rather than a feature, which is unusually well documented for a bug.

Strings gave fighting games a skill ceiling nobody had authored, splitting the audience between players who drill execution and players who do not, and setting off thirty years of balancing between them. Outside the genre, the same idea became the grammar of character action games, skateboarding scoring and superhero brawlers, where a string matters less for damage than for rhythm and spectacle. Combo breakers and bursts have been arriving ever since.