One of the defining characteristics in RPGs are stats. When you start out in an RPG your stats are terrible, but when you get towards the end your stats are so good that you practically become a god. However in some RPGs you have stats that... don't really matter. Stats that are just there to take up experience points. These are those stats.
More specifically the swimming stat in Deus Ex. Since you could swim automatically out of the gate there was practically no reason to level up the stat at all. Sure you could hold your breath longer... but how many areas in deus ex did that ever come in handy?
Only in the Mario and Luigi RPG series though.
Now why only Mario and Luigi RPGs? Because you can dodge thus removing all notion that you'll need a lot of hit points to get through the game.
Luck, normally a modifier in most role playing games, it usually determines the likelyhood of you getting a critical strike and thus is not considered as important to all other stats such as dexterity, strength, and hit points.
