This can be done with no tech at legit casinos. Just have a group of people with a predetermined “tell” system so that only the best hand in the group competes against the fish. In a 4 player game, with 3 teamplayers and 1 fish, thats 75% of games you’ll win. With zero tech.
Collusion in live casinos is a real thing for sure, but it's not exactly easy to pull off.
1) Most card rooms these days are 8 or 9 players, so your team would need to be at least 3, maybe 4 to really swing the odds in your favor.
2) You need a subtle but effective way to signal to your team the relative strength of your hand. Think baseball signals, but way more low key. "If I touch my watch, I have an Ace" etc. You'll probably want to mix these up across the hours or days of play.
3) Seats typically do open one at a time, and you want to trickle in your team to avoid suspicion. Higher stakes games, like $5-10, where there are thousands of dollars in front of most players are your goal, and good news is that these are typically more rare so there may be only one table running. Your teammates will have to wait it out, but once at the table, they can stay for hours.
4) You'll never know exactly what your targets are holding, but knowing that your teammates folded a flush draw for example can help you narrow your opponents cards to a smaller range of possibilities. You'll want to position your teammates around the table to create "squeeze" situations where two of the team can trap a target in between.
It takes some creative subtlety, but it can be very hard to impossible to detect collusion in live games.
* The casino takes a rake, so you lose money every hand, but you only win when the fish bets and loses. You’re also expected to tip the dealer
* Everything is on camera and dealers remember players, so there will be a lot of witnesses and evidence
* Seats often open one at a time, so you’d potentially lose money at other tables waiting to play together. Or, you all show up at once and ask to start a new table together, which would get suspicious.
* If you don’t know the fish’s cards, there’s still a chance you lose and lose big
