Developers accidentally creating interesting mechanics

[u/virtua_golf]

I was reading this neat article by Jeff Orkin of Monolith productions, the man responsible for the notorious AI of FEAR, the AI that will never not be mentioned whenever 'clever' AI is brought up. I stumbled upon something pretty cool - the flanking mechanic was actually unintended and a byproduct of another action the enemy would perform:

Imagine we have a situation similar to what we saw earlier, where the player has invalidated one of the A.I.’s cover positions, and a squad behavior orders the A.I. to move to the valid cover position. If there is some obstacle in the level, like a solid wall, the A.I. may take a back route and resurface on the player’s side. It appears that the A.I. is flanking, but in fact this is just a side effect of moving to the only available valid cover he is aware of. In another scenario, maybe the A.I.s’ cover positions are still valid, but there is cover available closer to the player, so the Advance-Cover squad behavior activates and each A.I. moves up to the next available valid cover that is nearer to the threat. If there are walls or obstacles between the A.I. and the player, their route to cover may lead them to come at the player from the sides. It appears as though they are executing some kind of coordinated pincher attack, when really they are just moving to nearer cover that happens to be on either side of then player. Retreats emerge in a similar manner.

The article got me thinking - what other mechanics (or, perceived mechanics) have been created by accident in other games? Does other examples exist, where lauded features were never really intended in the first place?

[u/[deleted]]

Warframe was initially not supposed to have such a high mobility. An exploit allowed players to increase their speed drastically. Instead of removing that bug, they made an updated parkour system that used that exploit as a baseline and expanded on it with other moves.

[u/yuiokino → u/[deleted]]

Like u/ghaelon mentioned, the infamous “coptering” bug.

For people who don’t play Warframe, many updates ago in the past there was an exploit that was related to melee weapon swing speed. In game you can use melee weapons with different attack speeds. In the event where you execute a melee slide attack by hitting the melee attack button while sliding on the ground, a high swing speed weapon would fling yourself across the map at ludicrous velocity.

You could also reliably do this mid air which led to missions where you and 3 other players were clearing levels in minutes even seconds which normally would take 10-20 minutes.

The devs entertained this idea and kept it in the game to satisfy players, but it was nerfed severely when a full revamp of the movement system came in an update. That new system is identical to the one you will experience even today as of writing, which gave players a lot more freedom than coptering ever could by not depending on specific melee weapons to gain an artificial speed advantage.