When you have noted that one or more of your opponents at a cash table is a LAG (loose-aggressive) player, you should slow down and form a strategy for crushing them. Picking them out shouldn’t be too hard because they will be open-raising with a very wide range, three-betting with a lot less than Jacks and making some big moves post-flop.
Ideally you want to have position on a LAG player, as being out of position on even a losing LAG can be a very tough situation. If you don’t get in crossfire wars with other players gunning for his chips, you’ll end up having to gamble, wait for the nuts or make some very big calls post-flop, none of which are easy or attractive prospects.
The most effective way of combating a loose-aggressive player is by playing a strong range. When you have a strong holding, all of your decisions are generally easier and you get into far fewer complex situations and marginal spots. It is tempting to get involved when you see a monkey LAG involved in every pot with less than stellar hands, but this is exactly the adjustment you should NOT make. Be patient, find a hand and let them bluff into you when you are comfortable with your holdings. It’s important to realise that an awful lot of the time a LAG will have a weak hand or nothing at all.
Leaving room for the bluff
You should be happy to let a LAG player bluff, so don’t start raising your set on a super dry 3-7-T rainbow flop. There is simply no need. These players are loose and aggressive, not necessarily dumb, and you won’t get full value by playing fast. Instead, play your hand like the bulk of your range. Call, let them barrel the Ace on the turn, call again and then break their arm off when they overbet on the river. Don’t lose sight of the fact that you make money from these guys by letting them indulge their aggression.
The other way to combat LAGs is by playing back at them, three- and four-betting them liberally pre-flop and bluff-raising or check-raising them on the flop. However, this approach will put you into a lot of high-variance standoffs, and in general actually holding or flopping a strong hand will be a far superior strategy.