Best practice for powerup implementations

Hi all,

I'm making a space shooter game, and I'd like to implement a lot of different buffs / debuffs in the game.

Some example: - Take Damage over time (x damage per second) - Double all damage dealt - Reverse controls

My first thought was to use "if" statement in my existing scripts and check for flags to see if a specific powerup is active, but that doesn't feel right in terms of code maintenance.

Moreover I'll probably think of a lot of other powerup ideas over the course of time, and it could quickly become a mess in this way. Not to mention that some powerups could mess with very different things, so their implementation would be scattered in the code. And I might also want to make them stackable.

Ideally I was hoping to find a way to make each buff/debuff as a prefab that would be instantiated as a child of the affected character. But how can I mess with the character's controls in this way.

I guess powerups are part of a lot of games, so I was hoping perhaps you guys can show me to a nice ressource where someone explains how those things are usually handled.

thanks in advance