14 'Genius' Video Game Features That Were Total Accidents

3. Combos In Fighting Games (Street Fighter II)

What you think: The grandaddy of fighters, Street Fighter II, came fully-formed with not only one of the best balanced roster of fighters, but everything from special moves to aerial attacks, ground dodges and - most importantly - combo attacks, right out the gate.

What really happened: Another glitch that came from testing, SF II's refined gameplay from the first included a rift of newer animations, but what the team didn't count on was the ability to chain them together. Fighting games and combos go together like Star Wars and lightsabers now, but old-school brawlers like these were only intended to give you one animation at a time.

Unbeknownst to Capcom, once some button-happy focus testers got hands on with the pre-release build of SF II, they discovered some moves could be chained together (like a low kick into a fast rising uppercut, for example). It was incredibly revolutionary, and although Street Fighter over the years has reclaimed its status as the one fighter that prioritises move selection over button-bashing, can still be celebrated as essentially the birthplace of combo attacks in general.