The best way to think about a table with 3 players is to consider it a table with 8 players, where the first 5 players have folded. So if you know how to play that situation, you also know how to play a 3-handed table. The folded hands have some slight card removal effects, but this can just be ignored, since its to insignificant to really matter.
Since there will never be action from early or mid position, and since you will never be in early or mid position yourself, ranges will be wider on average, and the pace of action will be faster. This will tend to punish nitty players, because you really cant afford to sit and wait for premium hands, when you are paying the blinds every two out of three hands.
So to be good at 3-handed game you need to be comfortable playing a lot of marginal hands, which you can often just fold in a 8-handed game. Like top pair no kicker, second pair, a bad draw and so on and so forth. You also cant afford to never bluff
, since the opponents are probably bluffing
you. And since you play against the same two people all the time, paying attention to dynamics become more important.
By this I mean, that if you instance you have C-bet the flop and then given up on later streets a number of times, then most likely the opponents have noticed this, and you should try to do something else. Like either not C-betting or continuing to apply pressure on the turn and river. Getting your frequenzy somewhat correct is often more important than your exact hand in shorthanded play.
And of course if its any kind of tournament other than a Spin n Go, then 3 players left mean payjumps, which mean, that understanding ICM becomes very important. Sometimes the distribution of stack sizes can completely override nearly everything else, as the mid stack basically just wants to try to outlast the short stack and secure second place money.