Spell Hit: What You Need
Posted: 12 Mar 2015, 20:00
This is to help new players wondering what they need for their class, and to explain why they need those stats
Spell Hit
In this expansion, the chance to hit a target of the same level as you with a spell (player and non-player) is 96%, this fact doesn't change based on class, it's the same for everybody. Also, because Blizzard hates you, the most hit you can get (physical and spell) is 99%. there will ALWAYS be a 1% chance to miss your target in this game. A spell missing will read as a resist, so don't confuse it for an actual resist, which I'll explain later on. So, of course you need 3% spell hit to have your 99% chance to hit your target, or the hit cap.
Sadly, it's not all that simple. Three talents exist that reduce the player's chance to be hit by spells by 4%, these talents belong to Subtlety rogues, Balance druids, and Retribution paladins (the former two are extremely common, as the Balance one is grabbed by restokins as well). This means that against those three classes, you need 7% spell hit to be capped. Keep in mind 7% spell hit is a LOT for PvP gear, probably impossible for a season 2 geared player. Luckily there are some talents that work opposite those three talents, and increase the caster's chance to hit with spells (these are generally school specific). So as a new player your best bet if you want to always have a 99% chance to hit is to get 3% spell hit from gear, then spec into these talents for another 4% chance to hit. For example warlocks can drop 2 points in Suppression, giving them exactly 4%, and therefore giving their Affliction spells a 99% chance to hit all enemy classes (in accordance with 3% spell hit from their gear).
Basically, you need 3% spell hit minimum, no less. You can get more if you can afford it, but it's probably not best to sacrifice more important stats for that extra hit percent against three classes. Consider your matchup against the classes and whether or not you really need the extra hit. For example as a warlock I know the very last thing I need is for a rogue to resist my death coil or a fear (if they do so, I'm dead), so I'm definitely going to get that 4% hit from Suppression.
Spell Pen
Next we have spell penetration, in order to explain it first we need to know how resistances work. Resistances in TBC are pretty different from every expansion after. Every time a spell is cast at you, it has a chance to do less damage if you have resistance to that school of magic. Spells will deal full damage, three fourths damage, half damage, one fourth damage, or zero damage (considered a "full resist", and shows up as a resist in game). If you have no resistance, spells will always deal full damage to you, but the higher your resistance is, the better chance you have of getting the one fourth or zero damage spell. So a warlock casts incinerate at you, if you have no resistance it will deal 1000 damage. If you have 10 resistance but you're lucky you might get a 3/4 resist, so it deals 750 damage instead. If you have 100 resistance then chances are you'll get either 250 damage or none at all, and fully resist the spell. This is why Felhunters seem invincible to casters, they are basically never taking full damage from a spell.
Spell penetration has reduces the target's resistance by how much spell penetration you have (a 1:1 ratio). So if the target has 100 fire resistance but you have 70 spell penetration then the target's resistance to your fire spells is only 30. For 1v1 purposes, you should never need any more than 70 spell penetration, as that's the most a self buffed player can reach without flasks. However for arenas and especially battlegrounds, resistances will get pretty high. In the worst case, an undead SL/SL warlock can reach 245 shadow resistance without flasks. Again, you'll want to go for a spell penetration that works best for your class against most matchups, you can benefit from up to 130 but getting that much is very hard without wrecking your stats.
So, in essence you need a minimum of 3% spell hit and 70 spell pen, everybody knows that but here's your explanation of why and perhaps why you might need a little more! Keep in mind even when fully capped resists may still happen due to RNG talents that reduce the player's chance to be feared, stunned, snared, or hit by AoE spells (these are all over TBC talent trees). For example a Destruction warlock will have a lot of trouble landing shadowfury due to AoE resist chance, stun resist chance, or just plain shadow resist (it's a hard knock life for us Destros :P)
If this is helpful I can do a followup on strategies to cap yourself and do the same stuff for PvE and melee hit.
Spell Hit
In this expansion, the chance to hit a target of the same level as you with a spell (player and non-player) is 96%, this fact doesn't change based on class, it's the same for everybody. Also, because Blizzard hates you, the most hit you can get (physical and spell) is 99%. there will ALWAYS be a 1% chance to miss your target in this game. A spell missing will read as a resist, so don't confuse it for an actual resist, which I'll explain later on. So, of course you need 3% spell hit to have your 99% chance to hit your target, or the hit cap.
Sadly, it's not all that simple. Three talents exist that reduce the player's chance to be hit by spells by 4%, these talents belong to Subtlety rogues, Balance druids, and Retribution paladins (the former two are extremely common, as the Balance one is grabbed by restokins as well). This means that against those three classes, you need 7% spell hit to be capped. Keep in mind 7% spell hit is a LOT for PvP gear, probably impossible for a season 2 geared player. Luckily there are some talents that work opposite those three talents, and increase the caster's chance to hit with spells (these are generally school specific). So as a new player your best bet if you want to always have a 99% chance to hit is to get 3% spell hit from gear, then spec into these talents for another 4% chance to hit. For example warlocks can drop 2 points in Suppression, giving them exactly 4%, and therefore giving their Affliction spells a 99% chance to hit all enemy classes (in accordance with 3% spell hit from their gear).
Basically, you need 3% spell hit minimum, no less. You can get more if you can afford it, but it's probably not best to sacrifice more important stats for that extra hit percent against three classes. Consider your matchup against the classes and whether or not you really need the extra hit. For example as a warlock I know the very last thing I need is for a rogue to resist my death coil or a fear (if they do so, I'm dead), so I'm definitely going to get that 4% hit from Suppression.
Spell Pen
Next we have spell penetration, in order to explain it first we need to know how resistances work. Resistances in TBC are pretty different from every expansion after. Every time a spell is cast at you, it has a chance to do less damage if you have resistance to that school of magic. Spells will deal full damage, three fourths damage, half damage, one fourth damage, or zero damage (considered a "full resist", and shows up as a resist in game). If you have no resistance, spells will always deal full damage to you, but the higher your resistance is, the better chance you have of getting the one fourth or zero damage spell. So a warlock casts incinerate at you, if you have no resistance it will deal 1000 damage. If you have 10 resistance but you're lucky you might get a 3/4 resist, so it deals 750 damage instead. If you have 100 resistance then chances are you'll get either 250 damage or none at all, and fully resist the spell. This is why Felhunters seem invincible to casters, they are basically never taking full damage from a spell.
Spell penetration has reduces the target's resistance by how much spell penetration you have (a 1:1 ratio). So if the target has 100 fire resistance but you have 70 spell penetration then the target's resistance to your fire spells is only 30. For 1v1 purposes, you should never need any more than 70 spell penetration, as that's the most a self buffed player can reach without flasks. However for arenas and especially battlegrounds, resistances will get pretty high. In the worst case, an undead SL/SL warlock can reach 245 shadow resistance without flasks. Again, you'll want to go for a spell penetration that works best for your class against most matchups, you can benefit from up to 130 but getting that much is very hard without wrecking your stats.
So, in essence you need a minimum of 3% spell hit and 70 spell pen, everybody knows that but here's your explanation of why and perhaps why you might need a little more! Keep in mind even when fully capped resists may still happen due to RNG talents that reduce the player's chance to be feared, stunned, snared, or hit by AoE spells (these are all over TBC talent trees). For example a Destruction warlock will have a lot of trouble landing shadowfury due to AoE resist chance, stun resist chance, or just plain shadow resist (it's a hard knock life for us Destros :P)
If this is helpful I can do a followup on strategies to cap yourself and do the same stuff for PvE and melee hit.