D&D 5E 4th level Bladesinger with same AC as Tarrasque

[Charlaquin]

They are very versatile -- I love Bladesingers, matter of fact. The cost of that versatility is that using it dilutes being an effective wizard. I see it as a fair trade -- you burn resources another wizard is using for different effects to be able to hang in melee, even occasionally defensively excel. Perfectly fine, for me. I don't have any problem with the OP situation -- plenty of game left around 25 ACs.

Agreed. As a magic player, I think of it a bit like modal cards. Each mode is slightly less efficient for its cost than the same effect would be on its own, but it’s usually worth it to have the other options available.

 

[MarkB]

Given that shield lasts one round and uses up a spell every time, the bladesinger can do this at most 3 times (having already cast Mage Armor) or perhaps 5 times (due to Arcane Recovery) before dipping into their 2nd level spell slots on any given adventuring day. If that's how the player wishes to play their character.

So, perhaps be sure to set up a combat no and then that has mobs so you can use mob rules (DMG p250). Or once in a while smarter enemies might notice the shield go up once or twice in a combat and then might try to do something that gives advantage on attacks against the bladesinger - knocking them prone, pack tactics, blinding them with sand to the eyes, etc.

Or, what @TwoSix and @Ovinomancer said.

Shield also takes a reaction, so provoke him into making an opportunity attack.

 

[Ovinomancer]

Shield also takes a reaction, so provoke him into making an opportunity attack.

Or just walk past them to the other party members after the first attack triggers the shield.

 

[UngeheuerLich]

Probably.... go away and come back a minute later... helps against quite a lot of characters actually.

 

[DND_Reborn]

So I have a 4th level bladesinger in my game who essentially has the same AC as Tarrasque...

10 + 3 (from 16 DEX) + 4 (from 18 INT) + 3 (from Mage Armor) +5 (from Shield) = 25

So he essentially can only be hit with crits... how would you deal with this??

Wait for him to run out of shield spells. Oh, and anyone with a +6 mod (easy even at level 4) to attacks can hit with a 19 or 20...

Also, a dispel magic would stop his shield and mage armor immediately--no check required.

 

[Helldritch]

As the earlier posters said, there are many ways to deal with a Bladesinger. What I would recommend is to not over do as to gimp the character. A bladesinger is a versatile character that is fun to play as long as the DM gives a fair chance.

The main problem seems to be, again, a monotype style of encounters. This is fairly common problem. As soon as a lot of your encounters includes more than one type of monsters (ideally 3 or more) a high AC is no longer a problem. A single acolyte can cast a bless spell, two thugs can grab and restain the charcacter forcing him to use more resources.

Yes, there are times that such high AC will be a pain in the ass. But it is also true that it comes at a high price and remember one thing:"Every character should have a chance to shine. "

 

[Khelon Testudo]

Let the swords and arrows bounce off him, so he feels like a hero. When you want things to get serious, target his wisdom, charisma, or even con saves.

 

[Flamestrike]

Dude; at 4th level he as 4/2 slots.

He spends 1 on Mage Armor, leaving him enough spell slots for 5 rounds worth of shield spells and no other magic at all for the rest of the day.

If a Wizard is wading into melee, and blowing his precious spell slots on shield, while swinging a sword about the place, then that's a total win for the Monsters.

 

[Ancalagon]

This really isn't a problem because the Bladesinger is spending all of their resources to do something a Fighter mostly does without effort, so they're not being the Wizard, just a dodgy fighter. The Bladesinger is much better used as a Wizard that can survive melee rather than a melee combatant that's occasionally a wizard. The lack of hp and poor saves vs CON and DEX mean that a lot of things really hammer a Bladesinger on the front lines. What's really killer is a foe that just knocks the Bladesinger prone, because AC and blur don't help with that at all, nor does Bladesong. Two enemies that knock prone and grapple make the Bladesinger easy prey for anyone else, and it's unlikely they'll have an easy time escaping -- even if they do, they aren't doing anything else.

The thing is, the bladesigner is not a good "gish". You can use your magic to enhance your sword-fighting, but with lackluster result. And your sword-fighting doesn't enhance your spell-casting. Almost any other build is better at fighting.

Now if you multi-class... then maybe it can work.

 

[FrogReaver]

So I have a 4th level bladesinger in my game who essentially has the same AC as Tarrasque...

10 + 3 (from 16 DEX) + 4 (from 18 INT) + 3 (from Mage Armor) +5 (from Shield) = 25

So he essentially can only be hit with crits... how would you deal with this??

Have enemies push him prone then grapple him. Nearly doubling your chance to hit/crit him will feel good.