What makes a home card game lagal/illegal when there is money involved?
I can't see how a group of friends and a couple of invitees over the house to play for a few bucks and a few laughs would be anywhere close to illegal.
Something tells me the men in blue should concentrate their efforts on the real crime problem.
If you're in the US, it depends on individual state laws.
If you are playing with your friends it's fine and you'll never have to worry about the law.
The laws are in place to stop "underground" card rooms from popping up. For example having games ran out of your basement with multiple cash tables 24/7 and charging rake would definitely be illegal.
I've always thought about opening up a "High Stakes" underground room. No windows, all guests have to wear blind folds and be picked up and dropped off at their own home. $50/$100 No Limit or $100/$200 No Limit with a 1BB Rake... would be killer. Have people working security with shotguns and stuff. Nice right?