Happens all the time…

Agree with hitchens97, although it's not just preflop fold equity. I only have live experience to suggest this is true, and solvers playing against each other probably hard disagree, but IMNSHO if you raise limpers preflop you can bluff significantly wider postflop (than if you just limped along) and that counts toward the equity of raising instead of limping.

I'd say two main "technical" points:

1. People vastly overestimate the value of limping along "nut making" hands (ignore the small cost that happens a lot, and the coolers, but remember the giant wins).

2. A big concern should be if people notice, and can exploit, that you've split your range badly at a very early part of the game tree.

...and I think the majority of what regs. actually do is heavily weighted towards ignoring both those points, Eg. limp behind all low Axs and pairs.

So in my opinion there are 2-2.5 viable technically sound options:

1. Just raise or fold, can mix folding/raising some hands. Reason: limping along sucks in a raked game so just don't.

2. Limp along a pretty big range, and raise something close to a 3bet range. Reason: You have the BTN; people see you in pots more often; and you're better than everyone anyway (Eg. you are much less likely to punt in giant SPR pots than others)

2.5. Same as #2, but randomly include any hand that is a limp as a raise (higher variance but much more difficult to exploit, but you probably need to get the randomness better than #1 because you'll be in a lot more hands).

And while I think it's possible game conditions can change which is better, I think #1 is basic obviously correct strategy that works everywhere ... and people overestimate when 0, or 2/2.5 is going to be better, because playing more hands is more fun and occasionally winning giant pots is more fun (and when you don't you just complain that you are unlucky and haven't hit a set in 666 attempts).

As a final point, I'd say that while "you are better" you probably aren't that much better at very common spots ... and something like strat. 0 is _very_ common, so other regs. will have the most experience with it ... then 2 is likely the next most common, and so bad regs. will again have a better idea what to do against it.

And this point works backwards too, because the more you do other strats. the more experience you get using those strats. ... and there are a bunch of 2-5 games I've played in where anything but strat. #1 is almost certainly losing.

There's something to be said for raising in position with hands that show +ev simply from their equity advantage over the field (i.e. putting in 1/5 the money but having > 20%), plus in most games you get a lot of free turns ("4-card flop") to realize more of that equity, plus you get the additional fold equity of being the pfr....
But anything pushed too far will start to misfire and you'll face more donkbets, LRRs, and other countermeasures.
Plus some hands might be +ev but play better in smaller pots. It depends...

Agreeing with the others. Unless the blinds are aggressive and 3bet, hero’s raise OTB followed by calls sets hero up for post flop. Hero now has an uncapped range in position against weak players with capped ranges. How many times do you expect to win 5 way? You’ll win more than 1 out of 5 times because your range is uncapped and you have position on everyone. But you are going to have to fold post flop most of the time.

After 3 limpers be raising to $25-$30. Getting everyone to fold is a good result anyway.

Key for me in all spots is SPR we're creating / IO we're offering (especially multiway) / stack sizes / etc.

For instance, at my purposely starting / topped up stack size of $200 in my 1/3 NL game, raising anything but absolute premiums after multiple limpers is a terrible idea, as is raising premiums to an amount that creates a small committed SPR while also offering all the multiple callers decent IO. But doing any of this at a much larger stack size might be fine.

Gitdepends,imoG

Matthew Janda talks about situations which occur very commonly where your strong hand would actually prefer a fold, but doesn't mind a call. Obviously your equity goes up to 100% when you get folds and most other situations (other than holding the nuts on the river) result in equities which are often surprisingly low.