Pot odds apply to multiway pots as faithfully as with heads up pots, however, when you calculate your odds, you have to do so against the combined range of all the opponents and only then can you justify the call.

Let's say you're the button on a 9 ring game and hold K2s. Before you there're 3 limpers and you expect the small blind and big blind to just complete and check if you limp too.

The total pot will be 6BB and you have to put 1BB to play so your pot odds are 1 in 6, that is, about 17%.

Now, to actually determine if you should play the hand you need to calculate the odds of you winning the pot with your hand. To do it, you need to check your K2s agains the combined range of the 6 players. They're limping so let's assume they limp with 80% of their range (note if you have a hud you can narrow that range based on their limping range, here I'm simplifying). Your equity with your hand is roughly 17% so, theoretically, just taking into account pot odds, limping is EV0.

Of course that doesn't take into account reverse implied odds on a hand like K2s. K2s is a hand that will likely win a small pot but potentially lose a big one (if you hit you K and someone else has another king).

Now, if you hold J4o for example, your odds will be 11% and thus limping with that hand is EV-

I agree with all you said. I was talking strictly about pot odds because that is what the question was about.

Obviously there’re too many other variables like implied odds and reverse implied odds as well as, specially, non mathematic stuff, like the kind of players that are joining the pot with you which I think are more important than the odds themselves, the fact of whether someone still to act may raise or not, the position as you said… With so many variables I was only answering the exact question of strict poker odds given a fixed range for the villains and genericly stating the rule that Pot Odds directly relate to the Odds of you winning the hand in an all in situation, without taking into acount later streets.

In general tough, I won’t event consider pot odds in that situation, I’d weight much more factors like how likely it is that I’m going to stack one of my villains if I hit my monster, how likely am I to get in trouble if my hand connects with the flop in someway or how much am I going to be able to outplay other players and that sort of considerations rather than my pot odds for limping into a pot.