War Caster lets you cast a single target spell instead of an Opportunity Attack. Polearm master lets you take an OA when a foe enters your reach when weilding a quarterstaff. There are numerous single target spells that would be good here. A great fallback would be Blade Ward (cantrip).
This is probably the best use for Blade ward. Normally this spell sucks because Casty McFingers should always have another plan for getting out of danger rather than wasting one of his known cantrip slots on Blade Ward.
This would work better on a warlock with Repelling Blast assumming that Eldritch blast would be considered single target enough to classify for polearm master. Having each ray in EB push the target 10' is very tempting.
Oh goddamn this is just so delicious
I'm not sure this works.
It seems ot imply you need to attack with the polarm.
Though, i havn't seen the full text yet (still waiting on my book).
mellored wrote:
borg285 wrote:
Unfortunately the spell you cast with the opportunity attack granted by Polearm Master requires you to target the creature with the spell you are casting. You can't cast Blade Ward for your opportunity attack because it doesn't target the creature that provoked the attack. It technically doesn't require you to attack with the polearm you are wielding. I brought this up in another Polearm Master thread the other day.
I just realized a complication: When you cast a spell that requires concentration it breaks your concentration of any other spell you have going on. This makes cantrips and a small list of spells the only viable spell to cast. This non-cantrip list is:
- Melf's acid arrow
- Finger of Death
- Disintegrate
- Chromatic Orb
- Harm
- Contagion
- Inflict Wounds
- Guiding Bolt
- Command
- Power Word Kill
- Power Word Stun
- Feeblemind
- Dissonant Whispers
borg285 wrote:
RAW it works, but don't expect all DMs to be on board with it. It's clearly not the intention of the rules.
You mean something like this? The Warpole Master
HeirRaktus wrote:
I'm not completely sure it works by RAW. A reach weapon only increases reach for attacks made with that weapon.
You can't hold a polarm and make an opportunity attack at a target ten feet away with your dagger.
That said I don't think it's particularly overpowered. If your DM allows it, go for it, but don't expect it to work in every game.
1eejit wrote:
As a DM, I wouldn't allow it.
Getting 4x1d10+5 and pushing 40' every time a creature gets within 10' of you sounds fun, but in the end it results in a broken game.
Suzume_Stjohn wrote:
Technically, Warcaster says the spell can only target the creature provoking the OA. It never says the spell has to be a single-target spell. If you can angle it right, you can throw out Color Spray or Sleep, even .. as long as it only targets the creature provoking and is only a casting time of 1 action.
1eejit wrote:
Mommy_was_an_Orc wrote:
1eejit wrote:
Ok it's fantasy so internal consistency be damned, right?
If that's how you want to play have fun with your Harry Potter pig-latin magic.
Mechanical and mathematic consistency is important to a game system. Being able to shoot a spell at someone because you're good enough with a polearm to provide a momentary distraction does not dissolve the internal game mechanics.
Feats break the rules. That's what they're designed to do.
I would never allow an opportunity attack from a polearm as a spell cast, unless there is some kind of mechanic in the future that allows a weapon to be charged with a spell or such. It is clear from the feat that the attack is meant to be used with the polearm in question:
"While you are wielding a glaive, halberd, pike, or quarterstaff, other creatures provoke an opportunity attack from you when they enter your reach."
A partial quote from the feat.
They could have added , with said ploearm, but I expect they beleive we have some common sense. 
Spacekase wrote:
Lawolf wrote:
Lawolf wrote:
Spacekase wrote: