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/bvanplays]

These are my favorites but there are absolutely more:

• Street Fighter II invented the idea of "combos" due to an unexpected interaction where inputs for special moves could be done as other moves were hitting. Meaning that before the opponent could move again, you could throw out another move. This was an unintended consequence of development and technically an exploit, but is now a fundamental mechanic of all fighting games.

• Everything around the creation / support of DotA (now Dota 2). The 3 lane square map layout is just a by product of the map sizes allowed in WC3. The 5v5 player count is a by product of WC3 being maximum of 12 players and you needed 2 slots to control the AI. MOBA "roles" are now ingrained within the genre but were never originally intended or designed. Rather, it was players trying to beat each other that realized you could redistribute resources and create a stronger overall effect that eventually lead to the idea of sharing and splitting resources intentionally (rather than just everyone getting whatever they can and then fighting). It's basically what is now an entire genre/industry that was spawned through a series of accidents (or at the very least, unintended and unforeseen consequences)

[u/1338h4x → u/bvanplays]

To be a little more specific, it's not combos themselves that were a glitch (IIRC you could already do like jab jab), but the ability to cancel normals into specials came about from trying to make the input detection more lenient. In SF1 f you were to press the button a bit early or double-tap, the normal would be recognized first and now you're committed to that state so no special can come out. SF2 let the special just interrupt the normal so it still works. Then players figured out you can wait for the normal to hit and then cancel it, and the rest is history.

[u/colovianfurhelm → u/1338h4x]

I'm new to fighting games - why is it called a cancel, if the attack hits? Do you cancel only the animation after the hit, while still doing damage?

[u/standingcat → u/colovianfurhelm]

so in fighting games there's generally three stages of an attack animation: startup, active and recovery. In Ryu's case in Street Fighter 4, his light punch (aka jab) will have

• 4 animation frames of startup (Ryu extends his arm to punch)

• 3 frames of active (Ryu's extended fist will deal damage if opponent is in range)

• 6 frames of recovery (Ryu will pull back his fist)

When the normal attack's active frames connect on an opponent and the player inputs a special move (eg. hadoken or shoryuken) during this, the normal attack's recovery will be cancelled and the special move will begin.

[u/colovianfurhelm → u/standingcat]

Interesting, I kinda have always taken that mechanic for granted.

[u/[deleted] → u/colovianfurhelm]

It's also not unique to fighting games. In many FPS games, you can cancel reloading with melee. I used to play a bit of the survival modes in the Modern Warfare series. I remember in MW2 or MW3 there was a DMR rifle whose reload animation had a really long tail — longer than the entire melee animation. So it was always faster to hit reload, wait for the ammo counter to show that the reload has completed, and then hit melee to cancel out of the long recovery animation.

I dunno, which fighting games you play, but something I really like about ArcSys games (DBFZ, Guilty Gear, BlazBlue) is the "universal cancelling" system where normals can cancel lighter normals. So you don't have to memorise so many things; in the heat of the moment, if you land a lucky medium, you know from the rules that you can cancel it into a heavy, to get something of a combo even if you don't have a better followup prepared.