Common game design myth suggests that a key fighting game staple, the combo, was originally a bug, caught before launch, but left in the design of Street Fighter 2 as a courtesy, and soon became a key mechanic as the genre advanced.
Even to this day, many modern games fighting have so many exploits, it's difficult to tell whether they were intentional. And more often than not, these glitches separate common players, from the professionals. 'Korean Backdashes' in Tekken 7, 'Kara throws' in Third Strike, and 'Option Selects' which can be in many fighting games.
My question then, especially if there are any pro/experienced designers around (and not just fighting game devs), is whether it's a common practice for designers to leave such exploits in their games, or are they really all just bugs?
I can't imagine that kara throws or option selects were intentional; Capcom has been trying to remove kara throws in
Street Fighter 5, which suggests that that one is unintentional and not deemed to be beneficial to the game. But Capcom historically has been very smart about deliberately adding unintended mechanics that have proven in the past to make gameplay deeper. After
Street Fighter 2, move cancels started appearing in all their beat-em-up games (
Devil May Cry,
God Hand) as a deliberate mechanic. In
Resident Evil 5, exploiting invincibility frames separated the best players from the rest. (if you pick up an item or climb a ladder at the exact moment a rocket from someone's rocket launcher is shot at you, it will pass harmlessly through your character)
As I play
Elden Ring I think about the way the dodge roll evolved from its beginnings in
Demons Souls to the point now where boss fights are deliberately designed so that players *must* use invincibility frames that (I presume) were originally merely a bonus. Nobody knew then that it would become the primary mechanic for testing a player's skill.
On the other hand, certain mechanics from early Souls games have since been removed in newer games. Strict input processing which causes a move input at the same time an enemy is hitting you to be executed *after* you take the hit, for example; I do not know whether that one was intentional or not, but it served to punish you twice for a single mistake--which is too cruel--and From wisely axed it.
I guess what I'm trying to say is that a wise developer like Capcom or From evaluates all mechanics intended or not, removes the ones that don't improve the style of games they're developing, and embraces the ones that do.