Space = jump
Z = pick up items
X = basic attack
C = main mob attack
V = main single target attack OR the attack with the fewest targets (such as crusher or branish)
B = knock back attack or an attack that propels the user forward
Q = usually unassigned, currently only used for "decent" skills
W = main party buff or summon (when no party buff is available)
E = booster, never anything else
R = main defensive buff
T = secondary defensive buff
Y = currently only used for stance on my paladin
U = unassigned, will be used for Maple Warrior
S = main secondary buff, summon, or attack (such as lightning charge, combo attack, or portal)
D = second secondary buff, summon, or attack (such as holy charge, panic, or swipe)
F = third secondary buff, summon, or attack (almost always fire based)
G = fourth secondary buff, summon, or attack (almost always ice based)
Shift = primary movement skill (dash or combat step) or primary debuff (threaten)
Ctrl = hp potion
Alt = mp potion
End = most used cooldown skill (hp recovery) or secondary movement skill (rocket jump is the only one to fit that catagory so far)
PgDn = nimble feet or second most used cooldown skill
Home = attack potion or third most used cooldown skill
PgUp = least used cooldown skill
\ = mount