1/2 nl fullring table.villian is an unknown asian kid but was seen limp/rr with JJ from UTG.Villian($100) raises $10 from UTG, 3 callers including my target fish on HJ who has about $350. Hero($450) has AsQh on BT.Whats the best line right now?3bet,flat or fold?UTG short stack range seems pretty strong like TT+,AQ+.

Range: unknown, should probably assume strong
Aggresson: hard to tell, would be helpful to know how the JJ hand played out. His bet sizing pre is kind of weak, but proportional to his stack size. The limp/rr was kind of strong. Certainly capable of playing fearlessly.
Directness: low.

Assessment: nit

Expect a 3bet to be called. Expect him to check flop, watch for the check-raise (don't bluff).

Personally I would flat pre and would check behind OTF on most boards. I'll call his (likely weak) turn bet if I have a pair, and probably call OTR depending on bet-sizing and runout. Consider bluff-shove if the board is scary enough and there's enough stack leverage at the time.

Watch his stack, if he makes a decent-sized bet or call anywhere along the way, he will be thinking about gii at some point.

This is based on certain assumptions, if you have any additional info on reads let us know. If you;re thinking, "oh he's definitely a nit, that dude's a rock" it's OK to fold pre.

Call seems best. If his range is that strong you don't want to raise, he will call or shove and you don't like either. Folding with all that dead money in the pot would be too weak.

What you want at this point is call now, hit the flop, play a small pot and see who has the best hand. Aiming for two streets of value most of the time. This plan is largely based on villain being unknown, so even if you hit the flop you probably will not want to play for stacks.

If UTGs range was just a little wider, like AJ+, then I'd like raise and could consider GII given his short stack.
I think the original post is a little confusing bc you have UtG with $100 but the "target" V is the HJ with $350? Maybe I misunderstood.
If you raise to $50, expect original raiser to jam and you're likely to play HU. Raising anything smaller doesn't make much sense given the dead money.

Given UTG's tight range and short stack, just calling and seeing a flop in position is probably the best play. I don't hate raising. I think your hand in this position is too strong to fold and raising probably kills your positional advantage bc it's so likely to just be a shove fest.

Call, play a pot in position.

doubt his range is that tight

Absent a read I'm just calling. Good hand in the best position. We can still win more in a side pot as well. A 3! will just isolate you with the original raiser and his $100 stack and everyone else will likely fold (which is bad).

I'm 3! To 35

Calling villains shove if it happens.

$30/call.

Call and leave the mark in the hand. 3b'ing just isolates you against someone you're racing for 50bbs against.

There are a lot of fat value situations when you flat and you hit top pair.