It generally deals with the motion and gestural components of spells. Tabletop games like D&D put on arcane spell failure-chances onto all of their armors based on how restrictive it is to movement, which doesn't really make a whole lot of sense, but nevertheless.
Honestly it's because all fantasy is based in tradition. In the video game version of the fantasy setting elves are always the same snooty, higher-than-thou race. Dwarves are stubborn warriors. Mages wear robes. Orcs are bastards. It's all part of the generic setting.
To ask this question is to question many of the standards of video game fantasy. I say 'video game fantasy' because I've encountered many a novel in which the case is very different.
All-in-all I think it became the standard that mages do not wear armor because traditionally in fantasy literature magic is not used as a tool to battle with. If you take magic from 10 high fantasy novels, I'm guess 6 or 7 times out of 10 magic is far more practical and less of a weapon.
Honestly it's because all fantasy is based in tradition. In the video game version of the fantasy setting elves are always the same snooty, higher-than-thou race. Dwarves are stubborn warriors. Mages wear robes. Orcs are bastards. It's all part of the generic setting.
To ask this question is to question many of the standards of video game fantasy. I say 'video game fantasy' because I've encountered many a novel in which the case is very different.
All-in-all I think it became the standard that mages do not wear armor because traditionally in fantasy literature magic is not used as a tool to battle with. If you take magic from 10 high fantasy novels, I'm guess 6 or 7 times out of 10 magic is far more practical and less of a weapon.