Re: Cold Mastery & Monster -res cap?
The maximum cap for negative resistance is -100%. A monster's resistance cannot go lower than -100%, at which point the monster receives 2x damage from a particular element.
Immunity means that the resistance is 100% -- or more. Infinity can break some cold immunities,
but not all. Cold Mastery does
not break cold immunity. If Infinity breaks a cold immunity, then Cold Mastery will come into effect.
In conjunction with Infinity, Some sorceress uses an item (usually a wand) that contains Lower Resist charges. Lower Resist is a necromancer curse that can lower -- and break -- immunity, and its effect stacks with Infinity/conviction.
Cold Mastery
The skill level for Cold Mastery is usually set at either 1 (to activate the skill and let "+ skills" equipment increase it,) 7 (-50% resist cold), 12 (-75%), or 17 (-100%). Most people consider anything over 17 as useless because (a) Cold Mastery does not lower cold resistance beyond the cap of -100%, and (b) Cold Mastery by itself does not break immunity -- it does not work at all on a monster that has 100% or more cold resistance.
Cold Mastery at 17 points = -100% resist cold. If a monster has 0% resist cold, then 17-point Cold Mastery will lower it to -100%, and the monster will receive 2x damage from cold attacks. If a monster has 50% resist cold, then 17-point Cold Mastery will lower it to 50% - 100% = -50%, and the monster will receive 50% more or 1.5x damage from cold attacks.
Cold Mastery at 20 points = 115% resist cold. If a monster has 0% resist cold, then 20-point Cold Mastery will lower it to 0% - 115% = 115%. However, resistance cannot go below -100%, so the monster's cold resist is set to the lowest cap = -100%. If a monster has 50% resist cold, then 20-point Cold Mastery will lower it to 50% - 115% = -65%, and the monster will receive 165% or 1.65x damage from cold attacks.
However, if a monster has at least 100% cold resist, (many have
more,) then it becomes immune to cold. No amount of Cold Mastery by itself will break the immunity. 20-point CM will
not lower it to 100% - 115% = -15%. It just will not work on that monster at all.
Infinity
Infinity has level 12 Conviction aura = -85% resistance to all elements. If a monster is not immune to a particular element and has less than 100% resistance, then Conviction will work at full effectiveness. In this case, the -85% resistance from Conviction is added to Cold Mastery. So, Infinity with 17-point Cold Mastery will lower a cold resistance by -85% -100% = -185%
However, when a monster is immune and has 100% resistance or more, Conviction works at only 1/5 effectiveness = -17% resist.
So, if a monster has anything up to 116% cold resist, then Infinity will break it. 116% - 17% = 99%, which means the monster is no longer immune to cold, and Cold Mastery starts to kick in.
If Cold Mastery is at 17 points, then the monster's cold immunity becomes 116% - 17% from Infinity - 100% from Cold Mastery = -1%.
However, if a monster has at least 117% cold resist, then Infinity will not break it. 117% - 17% from Infinity = 100%, and the monster is still immune. In this case, Cold Mastery will not work. Cold Mastery is calculated
only after Conviction successfully breaks a cold immunity.
Monsters that are cold immune often have resistances that are higher than 117%. Cold resistance can go as high as 160%, or probably even higher. So Infinity is useless on those monsters. Therefore, Cold Mastery becomes useless as well.
The reason why Infinity can break all lightning immunities is because the highest lightning resistance is 115%, (I believe.) 115% - 17% from Infinity = 98%. At below 100%, the immunity is broken.
Lower Resist Charges
Lower Resist is a necromancer curse that lowers -- and can potentially break -- monster immunities. The curse affects a radius. A sorceress can't cast Lower Resist, but she can use an item that contain charges of Lower Resist. The most common items that contain Lower Resist charges are wands.
Most Lower Resist charges are level 1 (-31% resistance) or 2 (-37%). Level 3 (-41%) is the maximum on an item and very rare, and requires very high levels to use. Items with level-3 Lower Resist are at "item level 99", and can only be purchased by a level 95+ character from merchants or dropped by a level 99+ monster.
When breaking immunity, Lower Resist also works at 1/5 effectiveness; so a level-1 Lower Resist works at -6%, level-2 at -7%, and level-3 at 8%.
The effect of Lower Resist stacks with Infinity for lowering resistance
and breaking immunities. If you have Infinity and use a level-3 Lower Resist charge, you can lower a monster's immunity (meaning having 100% resistance or more) by -17% -8% = -25%, enough to break a few more cold immunities but still not all. -25% is still not enough to break monsters that have 130%, 150% or 160% cold resistance. And they are out there.
Most unfortunately, during the game you can't know if a cold-immune monster has 115% (breakable with Infinity + Lower Resist charge) or 130% (unbreakable) cold resistance until you use a charge on a monster that does not seem to be affected by your Infinity. That is impractical. However, you can find out monsters' actual resistance values at
The Arreat Summit website.
