Quelle??
Unlike the melee combat system, spell crit makes absolutely no difference to hit chance. All spells, regardless of whether they are treated as binary or not, roll hit and crit separately. Conceptually, the game rolls for your hit chance first, and if the spell hits you have a separate roll for whether it crits.
Und zu Teilresists:
In addition, direct damage spells suffer from partial resistance, but again, that has no effect on whether a spell hits or not. A fully resisted spell due to spell school resistance is indistinguishable from a spell which didn't hit, which contributes to some of the confusion on the matter.
In the binary case, it's rather straightforward - in the average, a target with 300 arcane resistance facing a level 70 mage is completely unaffected by 64 of 100 Slows, while 36 take full effect.
For pure damage spells the mechanic is more complicated. A Fireblast which nominally would hit for 1000 damage can in fact do exactly one of the following amounts of damage: 0, 250, 500, 750 or 1000. Over many spells cast, the percentage of damage avoided matches the result of the above formula,
[...]
For DoT spells, the partial resistance calculation is applied on each tick.
Wobei gefühlt hier die Dots zu oft resisten, vor allem beim Shadow
Damit berechnet sich dein effektiver Crit-Wert aus (100% - Miss% - Resist%) * Krit%
Resist% ist dabei die chance auf Vollresist, also auch mit 200 Resi irgendwas im Bereich 1-2%.