Best way to script hitboxes? Heard .touched causes lag problems?

So I'm a rookie dev looking to make a fighting game I'd like to ask for some tips before I begin A) whats the best way to script hitboxes? This is for ranged projectiles (such as magic balls or beams) and for close ranged (swords, mouse click combat) Secondly how should I go on making moves, what I currently do is make a folder with the effects when a player attacks and tie it to the player who cast it,then add this to debris. Any general tips would be appreciated too!