In a fighting game, should an OP character receive nerfs or should their weaknesses be amplified to balance out their strengths?
It depends on circumstance. Nerfs make the audience angry. Buffing the characters below them is sometimes more appropriate. Which is appropriate depends on circumstance.
The key thing is, it should be identified which matchups the character dominates in and why they dominate those particular matchups, then those elements of the character should be tweaked so those matchups are 5:5. If characters below them are having that type of trouble, then their options should be reconsidered as well. You really want to preserve diversity while giving every character a way to beat every other character’s options. Part of a way of preventing imbalance in advance is to give characters defensive options across the board that can be used to nullify most options you can give a character, for example Guilty Gear’s myriad array of defensive and movement options tends to allow characters to at least nullify their opponent’s offense.
For example, Bowser in Project M has a really great getup attack from ledge, it’s hard to punish in conventional ways because it’s so fast and far reaching and leaves him pretty safe. However it can be beaten easily by any character just by shielding near the ledge and grabbing him when the ledge attack is done. Characters have these universal defensive options, spot dodging, rolling, air dodging, that help give them options even in bad matchups. Obviously this isn’t going to solve everything, a bad matchup is still a bad matchup, but it can help. Even if your character doesn’t have some of the more specialized tools that another might have to win in a matchup, you can fall back on these universal tools frequently to at least prevent the opponent from gaining too much of an advantage.
Part of it also comes down to the direction the game wants to go in. Sometimes a character’s moveset combines to create a playstyle the development team doesn’t want, which happened for a LOT of characters in Project M 3.02. If you keep going too far in the awesome offensive direction, you end up with a game where everyone has such great combos that people become afraid to aggress, or you get Hokuto No Ken, and that isn’t always what you want.
On paper it sounds good to always buff the underdog, because people hate nerfs, but it’s a question of getting the game into the playstyle where you want it to be. On the other hand, don’t just hand out nerfs all the time or your playerbase will feel punished for improving with characters only to see them get nerfed, especially true with lower tier or lesser played characters.
Amplifying weaknesses to balance out strengths is a concept that only makes sense on paper, with a very one-dimensional understanding of character balance. Weaknesses tend to be situational to the matchup. The matchup tends to determine what counts as a weakness in the first place. Yeah a character might be vulnerable to up throw chaingrabs, but if their opponent doesn’t have an up throw chaingrab or a good followup on their up throw, then it doesn’t matter much. Sure a character might be susceptible to shield pressure, but amplifying that weakness will lead to them getting crushed in shield pressure matchups, but run unopposed in matchups where the opponent can’t do much shieldpressure.
If all the matchups are 5:5, then no character can be S tier.