UNDOCUMENTED MECHANICS
"Mana Steal", "Life Steal" above follow a diminishing curve, not a flat gain per level; the other numbers in the same block do not: "Mana Steal": +72% at level 1, +125% at 5, +152% at 10, +176% at 20, +200% at the limit; "Life Steal": +72% at level 1, +125% at 5, +152% at 10, +176% at 20, +200% at the limit. Reaching the limit takes skill level 60, gear bonuses included, so the first few points are worth far more than the last ones.