hero - Ah3s5c7c (291 bb)
villain - xxxx (121 bb)

action - hijack posts bb. folds to hero on lojack. hero bets pot to take down dead money. instead hijack calls. small blind folds. big blind (villain) calls.

flop is Ac3hQh. villain checks. hero bets half pot. hijack folds. villain calls.

turn is Ad. villain checks. hero bets half pot. villain calls.

river is Td. villain bets pot.

villain is a known maniac that will play any 4 cards. 19 hands prior to this hero scooped a 221 bb pot vs villain so there is incentive to get back at hero.

questions:

1. is hero's play pre flop good/bad?

2. is the half pot bet on flop good/bad?

3. is the half pot bet on turn good/bad?

4. is villains pot bet on river an insta call scenario?

pre's fine

i bet bigger OTF. your hand's a solid 2-way hand but nothing's in cement. betting stronger defines your hand, whereas a half pot keeps people in with more draws when you aren't super strong one way or the other.

definitely bet bigger OTT as played because you figure to be leading at least for the high and you wanna get value in case he has a better low draw and bricks river. or charge him for a random big ace. a lot of times you'll see people call flop with AK or AJ etc. he didn't c/r turn though which is super weird so you figure he never has AQ or QQ.

river lead is pretty weird. first of all he's representing a FH. like he thinks his bet represents a value bet trying to get something from you. but if you already have a FH, you'd just keep betting that anyway, and if you were on a draw or a random A, you'd fold that to a river lead also.

second you kind of have to be wondering what kind of FH he has, if he has one. it kind of looks like he's repping a rivered AT, which is kind of believable if he called flop with ATKx or something similar.

i mean really i'd have no clue what an A4C player would be thinking or betting here. i just know that i'd call the bet and expect to see 24xx or ATxx or something similar. biggest takeaway should be that when your hand's somewhat middling both ways, betting stronger to define your hand will help you see the overall picture more clearly.

Wp so far, river call since he is repping exactly AT and you have an A blocker. It's kinda bad to have Ah but on the other hand you don't block any 2 or 4.

Bet bigger on the turn for sure, I'm not afraid to fold river here but op doesn't give enough info on villain (just a preflop range is not enough) , if he makes spazzy plays then it is a clear call

my apologies. villain as stated is a known maniac. will play any 4. she is not afraid to shove/call with a straight into paired/flush boards particularly if she puts hero on AAA and busted low draw (this was hero's initial hunch). when hero tried to get her to talk she (normally chatty when spoken to) was silent. she is capable of slowplaying AQxx here as well and make very unconventional plays. villain will not bluff with air out of position so the only hands she could have are KJxx, 33xx, TTxx, QQxx, ATxx or AQxx. villain will also chase non nut flushes so having the Ah vs her doesn't really matter. if she makes her flush she will either lead or call a bet. she will call a 3 bet too so hero never does the nut blocker bluff on this player... anymore. have tried and failed to bluff villain with the ace blocker on flush boards - all fails.

not too worried about the end result. few hands later hero had aces full vs 2 alls in on the flop so session was quite good just wanted to know if flop and turn plays on this particular hand were good/bad.

initially I put her on a flush draw/gutshot so when the ace came on the turn I decided a half pot bet was good enough to keep her in so when she makes her straight/flush she will definitely check-call a pot river bet. I thought if she had AQxx she'd 3bet me on the turn too. if she had 24xx I block one of the 5s and even if she does make a wheel I make a bigger boat. so the pot lead on the Td was really puzzling. ATxx is a possibility as shes only losing to AQxx. she does the same thing if she had KJxx here so lost my mind for a while there. I did fold tho

folding full houses in PLO games is generally not advisable

Although OP stated villain was a maniac, he didn't say she was stupid. Only that she lost a big pot to him. Well, that can happen with one bad river card. Given the action I think the fold was okay. Aggressive and stupid do not collide as much as one would like. I mean what can she have to lead out? 2,4,tt? A,2,4,q, maybe. .. probably ..

calling here isn't because villain is "stupid." it's because villain is representing a really narrow range and the bet is really weird.

villain can be making a play at the pot trying to fold out trips. or mistakenly putting hero on the wrong hand because they're misunderstanding hero's perceived strength because of his half-pot bets. has nothing to do with stupid.