To Sentinel, or Not to Sentinel, that is the Question

[Expected]

Should I, as a melee High Elf Arcane Trickster Rogue/Fighter with 8-17-13-16-12-8 wielding a rapier, dagger, or shortsword (whichever is magical) and a shield who plans to cast Haste on himself/ask someone to cast it on me, take the Sentinel feat? If I do, I can theoretically double my DPR and almost guarantee it activating because of Mirror Image. However, it competes with Uncanny Dodge, Evasion, and the ready an action reaction requirement from Haste + Ready for offturn Sneak Attacks and it is pointless if the ally next to me has it, too.

As of now, I am no longer considering Sentinel in my build, but I am willing to change my mind. Should I take Sentinel? If so, why? If not, why not? Are there better choices? I know how good Lucky, Resilient, and Elven Accuracy are and plan to take those already (Resilient for 14 Con and Elven Accuracy for 18 Dex).

[Greywander]

I see Sentinel primarily as a tanking feat, so I'm always slightly confused by people who think it will somehow allow them to consistently attack off-turn. I mean, given the choice, would you attack the meaty barbarian and take another Sneak Attack from the rogue, or would you attack the squishy rogue and not take an extra Sneak Attack? This is why the tank should take Sentinel instead, to encourage enemies to attack them instead of their squishier allies.

I would definitely talk to your DM and find out how they intend to treat Sentinel in your game. Will it be basically a free attack because enemies are stupid and will stupidly attack the tank anyway, or will you just make yourself an even higher priority target? Also, will your DM let it trigger off of Mirror Image, or does that still count as targeting you?

[Expected]

Mirror Image's RAW ruling allows Sentinel to trigger if one of the images are attacked. I personally do not like home rules and prefer RAI > RAW > Homebrew, but if the DM says otherwise, I have to agree or find another table. As for being a more enticing target, Blur imposes disadvantage on enemies who decide to attack me. I will also have 20 Dex by level 8, a shield, and studded leather armor, so I will have 12 + 5 + 2 = 19 AC at level 8 as well as disadvantage for enemies if they still decide to attack me with Blur active.

[JellyPooga]

I mean, given the choice, would you attack the meaty barbarian and take another Sneak Attack from the rogue, or would you attack the squishy rogue and not take an extra Sneak Attack?

Depends how squishy the Rogue really is, doesn't it?
Nothing stops a Rogue from beefing up with decent Con and d8 is middle of the road; no-one acuses Clerics of being squishy and they have far less defensive class features than Rogues do, excepting spellcasting. Don't fall into the trap of thinking a Rogue must automatically be "squishy" or that a Rogue cannot tank.

Sentinel is a feat that was practically designed for Rogues and does not compete with Uncanny Dodge, but rather they complement one another; attack the Rogue and he uses UD to mitigate half your damage OR attack the Rogues mate and he uses Sentinel for an extra Sneak Attack; win-win for the Rogue. Either he successfully tanks a hit that would otherwise target an ally, or he gets to double his very significant damage output.

On the other hand, Sentinel does compete with the Haste trick. That said, if you have Sentinel, the Haste trick (while typically more reliable) is somewhat redundant and you can essentially save the spell slot (a precious resource for an AT, let alone a multiclassed one) for another spell or for when you don't think Sentinel is going to be effective (e.g. you don't have an ally handy).

[Specter]

Evasion doesn't use your reaction, so don't worry about that.

[Expected]

On the other hand, Sentinel does compete with the Haste trick. That said, if you have Sentinel, the Haste trick (while typically more reliable) is somewhat redundant and you can essentially save the spell slot (a precious resource for an AT, let alone a multiclassed one) for another spell or for when you don't think Sentinel is going to be effective (e.g. you don't have an ally handy).

Would it still be beneficial to have Haste cast on me from an ally, even though I will be using Sentinel/Uncanny Dodge for my reaction? And even though, from your good advice in the other thread, it would be better for me not to cast concentration spells on myself, should I cast Greater Invisibility on myself during combat instead? How helpful would that be? I imagine it synergizes well with Sentinel, but would the enemies see my Mirror Image images?


Evasion doesn't use your reaction, so don't worry about that.

Oh, I didn't know that!

[MaxWilson]

And even though, from your good advice in the other thread, it would be better for me not to cast concentration spells on myself, should I cast Greater Invisibility on myself during combat instead? How helpful would that be?

As an Arcane Trickster/Fighter, you will never be able to cast Greater Invisibility in the first place so it doesn't matter. A pure Arcane Trickster could cast it once per day at 19th level, but when you split your class levels you lose out on higher-level spells, unless you're taking only one Fighter level. And if you're not taking enough Fighter levels to get extra attacks then you don't really need Greater Invisibility: you can get advantage on one attack per round plus hiding between turns simply by using Cunning Action to Hide in any handy heavy obscurement (even Fog Cloud if you need to) after making your attack.

[Expected]

Originally, the plan was to multiclass Arcane Trickster Rogue 19/Fighter 1, but now I've been convinced to do Rogue 18/Bladesinger Wizard 2. With that, I would have been able to cast Greater Invisibility, albeit at level 20 (which would probably never happen.

I was going to use Find Familiar (Owl)/Versatile Trickster for advantage.

[CTurbo]

Sentinel is VERY much an offensive feat as well as a tanking feat. I love Sentinel on Rogues and would take it before lucky 100% of the time.

Lucky is a really good feat but I don't think I'd ever consider is before level 16. I view it as solely a high level nothing better to take feat.

[Hadoken]

However, it competes with Uncanny Dodge, Evasion, and the ready an action reaction requirement from Haste + Ready for offturn Sneak Attacks and it is pointless if the ally next to me has it, too.

If I were you, I probably wouldn't take it for exactly the reason you've outlined here. It competes for the single reaction you get per round with other strong options. I strongly considered sentinel on my EK fighter, but ultimately decided against it because I already had other abilities to use my reaction on, so the opportunity cost of the feat wasn't worth it.

[LtPowers]

Mirror Image's RAW ruling allows Sentinel to trigger if one of the images are attacked.

As an aside, I'm not buying this.

Even acknowledging that the mirror image spell causes the attack to target something other than the caster, and that Sentinel doesn't require the attacker to attack a creature (just some target other than the Sentinel)...

The mirror images are duplicates of the caster and mimic its motions. If the caster has the Sentinel feat, then so do the mirror images. And Sentinel (the provision under discussion here) only triggers if the alternative target doesn't have the Sentinel feat.

(And besides, I think RAI should be that the attacker must intend to attack something other than the Sentinel to trigger it.)


Powers &8^]

[Hadoken]

(And besides, I think RAI should be that the attacker must intend to attack something other than the Sentinel to trigger it.)

That seems like a reasonable interpretation of RAI, but I have to say I like the cheekiness of trying to get sentinel to apply to your illusory duplicates. The mental image of some mook missing you and then getting whacked for it is hilarious. Still, definitely the sort of thing to run by your DM before committing to building around it.

[Expected]

According to RAI, effects (like Invisibility) affect the Mirror Image images, too, essentially making them useless. However, I think that since these images don't have the EXACT same stats (they get 10 AC + your Dex mod), they will also not have your feats--this is supported by the fact that Tough does not increase their hit points; they are assumed to have 1 hit point and dissipate if hit. It works RAW, but it's up to the DM's discretion.

[NaughtyTiger]

It works RAW, but it's up to the DM's discretion.

Only if the duplicate counts as a target.

The spell doesn't say it creates a target.
the spell doesn't say you can target the duplicate intentionally. (stretch on my part)
It is the target of an attack (hint that it IS a target)


Saying it's RAW is a stretch. i would let it fly at my table.

Additionally, duplicate is not explicitly an enemy by RAW, so sneak attack may not apply.