Understanding Spell Interruption: How to do it?

[Deadalready]

It never really came up before this point and it never seemed useful before so I kinda ignored it but just recently there have been times when interrupting a mage's spell has become critical.

The rule book seems a bit vague in how to actually *perform* an spell interrupt merely what the concentration rolls after being hit are. It seems to me that it's far too easy for a mage to 5 foot step out of any threatening attackers and avoid any attacks of opportunity/readied actions that would stop their casting. Unless a mage is surrounded then there's really no chance to interrupt a standard action spell???

So how does a melee player interrupt a spell?
Rule book reference page would help too.

[LazarX]

You essentially have to do the same thing a counterspelling mage would do.

You have to ready an action to strike at the time of casting. If you hit, you will force the concentration check to be further penalised by the damage you do.

This also holds true for archers or thrown melee weapons as a player found out the hard way in a PFS scenario I ran.

[SlimGauge]

Your readied action can include a five-foot step (unless you moved during the turn when you readied). This is key, because otherwise (as you've pointed out) the caster will five foot step away from you. The other way would be to have a reach weapon or a whip.

[Sir Gavvin]

I like a readied action and a wand of Magic Missile at 5th caster level. An automatic 6-15 point penalty on the concentration check.

Bonus points if you have a familiar that can use wands, so that you don't have to give up your own action.

[CaptainJandor]

oooh that's clever, sir gavvin! especially the familiar part ...

seems more reliable than trying to counterspell, too (unless the caster has Shield up, lol).

also a good reason to pick up the Step Up feat chain. That could be nasty on an eidolon, now i think about it ... or an animal companion maybe?

[LazarX]

SlimGauge wrote:

Your readied action can include a five-foot step (unless you moved during the turn when you readied). This is key, because otherwise (as you've pointed out) the caster will five foot step away from you. The other way would be to have a reach weapon or a whip.

Or as I've shown before, a throwing weapon or missilier at the ready.

[Kimera757]

Deadalready wrote:

It never really came up before this point and it never seemed useful before so I kinda ignored it but just recently there have been times when interrupting a mage's spell has become critical.

The rule book seems a bit vague in how to actually *perform* an spell interrupt merely what the concentration rolls after being hit are. It seems to me that it's far too easy for a mage to 5 foot step out of any threatening attackers and avoid any attacks of opportunity/readied actions that would stop their casting. Unless a mage is surrounded then there's really no chance to interrupt a standard action spell???

So how does a melee player interrupt a spell?
Rule book reference page would help too.

A wizard is probably casting a spell every turn, so forcing them to provoke every turn isn't fair. The 5 foot step is more important than the Concentration check though, as you've noted.

The key to stopping a wizard from casting is two-fold:

1) Use a fighter.
2) Use a wizard.

Now for more detail.

1) A fighter with a reach weapon and some kind of "off-hand" attack (eg Improved Unarmed Strike), or just a Spiked Chain, can threaten a wizard they're next to and one who has move 5 feet away. Get in the wizard's face and they have to either have to cast defensively or take an AoO and possibly fail their Concentration check anyway.

A fighter with Step Up can do something similar.

A fighter (or ranger, or anyone else who uses ranged weapons) can ready an action to shoot the caster when they cast a spell. Anyone with Manyshot is particularly good with this. I don't think you can "ready" Rapid Shot because it's a full-round action.

A monk (or any other kind of grappler) can be murderous against a caster. Even better if you trip them, because they can't take a 5 foot step and cast. (Probably.) Even nuttier if you can "disarm" them of their spell components, but if done to a PC, expect a rage quit.

2) Similar to the archer example above, a caster can ready an action to drop a Fireball (or Scorching Ray or other such direct damage spell) on the other caster when they cast a spell. This is not Counterspelling. You don't need to have or even know what spell your opponent is casting. There is no caster level check either, as you're not using Dispel Magic. You drop the spell, they take damage and then make a Concentration check to not lose their spell. Direct damage spells do a lot of damage compared to how quickly a caster's Concentration score scales.

If you're a blaster mage and you're targeting a caster, you should always do this. At worst, they take the damage they would have anyway. At best, you fizzle their spell. (I would ready an action to Disintegrate a mage rather than just Disintegrate them.)

In an Eberron campaign I was in, now some years ago, my party got into a fight with a trio of higher-level bad guys: a cleric, wizard, and barbarian. Someone stabbed the wizard to death so fast it was basically us versus two bad guys.

I readied an action to drop a Fireball on the cleric if he cast a spell. Alas, that spell was Mass Cure X Wounds on the barbarian (who really needed the healing by this point). The cleric just barely made his saving throw, and still took over 20 damage because I had rolled well. Then he barely made his Concentration check. Had the cleric failed his save (very likely), he could have been forced to make a Concentration check of at least DC 45, plus the level of the spell he was casting, so 50+. That would have been mathematically impossible.

Darn cleric and his lucky Reflex save!