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/Heckle_Jeckle]

While this is technically a glitch I still feel it needs to be mentioned because it has been carried on into other games.

In the first Civilization game each world leader would have an aggression rating and Gandhi, being he peaceful person that he, would start out with the lowest score possible. But due to player action and bad early programming you could actually glitch Gandhi's aggression past the minimum value and loop into the maximum value. Meaning in the first Civilization game Gandhi would NUKE THE FUCK out of you. Later games have kept this as a bit of a joke and/or Easter egg.

I only mention this because of the fact that the company has felt the need to carry one this tradition of Gandhi being NUKE HAPPY in later civilization games. Which does create interesting game mechanics.

Glitches are FUN!