Overview:

Lots of games which RPG-like statistics allow for character "buffs", ranging from simple "Deal 25% extra damage" to more complicated things like "Deal 15 damage back to attackers when hit."

The specifics of each type of buff aren't really relevant. I'm looking for a (presumably object-oriented) way to handle arbitrary buffs.

Details:

In my particular case, I have multiple characters in a turn-based battle environment, so I envisioned buffs being tied to events like "OnTurnStart", "OnReceiveDamage", etc. Perhaps each buff is a subclass of a main Buff abstract class, where only the relevant events are overloaded. Then each character could have a vector of buffs currently applied.

Does this solution make sense? I can certainly see dozens of event types being necessary, it feels like making a new subclass for each buff is overkill, and it doesn't seem to allow for any buff "interactions". That is, if I wanted to implement a cap on damage boosts so that even if you had 10 different buffs which all give 25% extra damage, you only do 100% extra instead of 250% extra.

And there's more complicated situations that ideally I could control. I'm sure everyone can come up with examples of how more sophisticated buffs can potentially interact with each other in a way that as a game developer I may not want.

As a relatively inexperienced C++ programmer (I generally have used C in embedded systems), I feel like my solution is simplistic and probably doesn't take full advantage of the object-oriented language.

Thoughts? Has anyone here designed a fairly robust buff system before?