When an auto-attack lands (does not dodge/parry/miss) that can proc a seal the of the following things happen independently of each other (see 2 roll system).
1) A "hidden strike" which uses melee combat mechanics occurs. If it lands it refreshes/stacks SoV DoT. Only white swings can trigger a refresh or stack. (This hidden strike mechanic can also proc things like berserking..)
\\wat the fack is going on here w/ hotfixes, update this later
2) A weapon damage based proc will occur if you used a special (CS/DS/judge) or if you have a 5 stack (from auto attacks). This attack can not be avoided.
опять же вот сама механика наложения дота