Poker you can count cards and will win something like 51% of the time if you do... but of course the house doesn't let you win, they kick you out. if I am not allowed to play to win why would I play?
Counting cards can give you the edge in black jack (not poker). It's not illegal, but highly frowned upon by all casinos and they will kick you out and ban you if they catch you. They like to keep the edge in their favor.
You don't count cards in poker. You also don't play against the casino (you play against other poker players). The casino will either charge you a set amount of money per hour to use the seat, or they will take a small percentage (called a rake) of each pot. The casino gets paid regardless of who wins at poker. Poker is the only game (with the exception of black jack - if you count cards) that you can actually win money in the long term. All other casino games the house has the edge and you will lose money if you keep playing - that is how casinos make money.
[edited to add - If you are dominating a poker room and it's causing other players to leave then the casino might be losing money and they can kick you out for that. as long as people are still playing and dumping money though the casino is getting theirs and they don't care if you win. This is why there are professional poker players, but no professional slots/craps/roulette players]
Why would you continue to play? You either
1. acknowledge that you are going to lose money and are willing to pay that cost in exchange for entertainment
2. don't acknowledge that as fact and keep playing thinking you will win money (but you won't), or
3. you are addicted and have a gambling problem.
If you play perfect by the book 7 deck shoe blackjack you should win theoretically I think like 50.1% of the time. The problem is that many casinos have slightly changed the rules. For example if you wander onto a table that pays 5:4 or 7:5 instead of 3:2 on blackjack, you found a loser table. The best way to play blackjack is to play perfect by the book and have as many complimentary drinks as possible. Your .1% loss should be less than the free beverages :-).
wrong you do not have an advantage even at 3/2 a casino doesnt play a game where you EVER have an advantage greater than 49.9% it doesnt make sense for them to do this. people who dont know odds stop posting that you can make money playing blackjack without counting - and counting doesnt work without 2 people and at most 2 decks
Time to put some of this nonsense to bed:
Blackjack:
1. You CAN count with one person. Obviously you would need to practice to do it effectively. If you're referring to the MIT team that employed multiple people to count, it's because they didn't want to be obvious about it. Once you're obvious about it, then the casino kicks you out.
2. You can count with 1 deck or a million. With card counting in Black Jack, you have a statistical edge in the
long run, which means it doesn't matter how many decks you have. The odds are the same.
3. Counting only works if the deck (or decks) has a memory, which means the deck isn't shuffled after every deal (i.e. there IS a discard pile of used cards that are known 100%).
4. Using perfect basic strategy but no counting still puts you at a disadvantage when compared to the house, albeit a smaller one than if you were to not employ basic strategy.
Craps:
1. If left to random chance, the house has the edge (as with all casino games, obviously).
2. There is a theory that you can toss the dice so that statistically you will get certain combinations more than others. In the
long run, and if done correctly (takes years and years of practice), will give you the edge, since you are tossing what favours you in the long run. Google "Dice Dominator," some guy that can roll what he needs the majority of the time (in the long run).
There is no house game in the casino that, if left to 100% randomness, gives the player the advantage.
Obviously, many people have been trying to "control" this randomness over the past few decades, sometimes legally (card counting, dice controlling, etc.), and sometimes illegally (past posting, using equipment, etc.).