How Good is the Polearm Mastery+Warcaster Combo On a Gish?

[ATHATH]

As the title.

Basically, those two feats together let you cast a spell as a reaction on any hostile creature that enters (or leaves) your reach. Is this good enough to spend an extra feat on if you're already picking up Warcaster, even if you have no use for the other benefits given by having the Polearm Mastery feat? Is it worth, say, both spending an extra feat and dipping Monk 1 to be able to use this combo (with a quarterstaff) on a Bladesinger Wizard without having to be MAD?

[RSP]

As the title.

Basically, those two feats together let you cast a spell as a reaction on any hostile creature that enters (or leaves) your reach. Is this good enough to spend an extra feat on if you're already picking up Warcaster, even if you have no use for the other benefits given by having the Polearm Mastery feat? Is it worth, say, both spending an extra feat and dipping Monk 1 to be able to use this combo (with a quarterstaff) on a Bladesinger Wizard without having to be MAD?

I don’t think it’d be worth it, even if you rolled very well on your stats. You need to up Dex and Int and probably Con if you’re in melee regularly enough to use the PAM Reaction attack. Plus, as a Bladesinger, you really want your Reaction for defensive purposes (Shield, Absorb Elements and the 10th level ability).

That said, if it’s the character you want to play, nothing says you have to optimize.

[ATHATH]

I don’t think it’d be worth it, even if you rolled very well on your stats. You need to up Dex and Int and probably Con if you’re in melee regularly enough to use the PAM Reaction attack. Plus, as a Bladesinger, you really want your Reaction for defensive purposes (Shield, Absorb Elements and the 10th level ability).

That said, if it’s the character you want to play, nothing says you have to optimize.
I'm using point buy, but yeah, I didn't think about the action competition with Shield and its ilk.

[Arkhios]

I'd argue, though, that Polearm Master + Spell Sniper (with Booming Blade) + War Caster is a very effective combo, but again it eats up on your ASI's, so there's a huge opportunity cost. Still, being able to cast Booming Blade with a 10 ft. reach as an "Opportunity Attack" when someone leaves - or enters (with Polearm Master) - your threatened area, is pretty damn nasty ability. One of my players had an Eldritch Knight who used this build and god damn was he difficult to get past. (as a "bonus", he was a variant human so he had all this at level 6...)

[Corran]

I would like to try an 8th level variant human battlemaster fighter with all of warcaster, PAM, spell sniper and mobile, at some point. Pretty sure he would end up falling off from a cliff at some point, it would probably be a fun build until then.

[Arkhios]

I would like to try an 8th level variant human battlemaster fighter with all of warcaster, PAM, spell sniper and mobile, at some point. Pretty sure he would end up falling off from a cliff at some point, it would probably be a fun build until then.

Spell Sniper requires that you are already able to cast at least one spell, unfortunately. You'd need a level in a spellcasting class or magic initiate :(

[Corran]

Spell Sniper requires that you are already able to cast at least one spell, unfortunately. You'd need a level in a spellcasting class or magic initiate :(
Oh... EK then would have to do. Though I really wanted to avoid pairing PAM with warmagic.

[RSP]

I'd argue, though, that Polearm Master + Spell Sniper (with Booming Blade) + War Caster is a very effective combo, but again it eats up on your ASI's, so there's a huge opportunity cost. Still, being able to cast Booming Blade with a 10 ft. reach as an "Opportunity Attack" when someone leaves - or enters (with Polearm Master) - your threatened area, is pretty damn nasty ability. One of my players had an Eldritch Knight who used this build and god damn was he difficult to get past. (as a "bonus", he was a variant human so he had all this at level 6...)

Using any weapon with reach means no Bladesinging benefits due to 2-handed. It kind of defeats the point of what OP was looking to do.