The theoretical house advantage for some casino games is fairly small, e.g., about 1% for optimally-played craps. This means that over the long term, a good craps player might get back 99 cents for each dollar they play. If they hit a "hot streak," they might even win some money. In practice, the actual house take for most games is fairly large (about 25% for table games) because people rarely play consistently, they reinvest their winnings, and the casino environment is intentionally designed to be noisy and visually distracting. Thus, for a given psychic to make any notable differences in long-term casino profits, they would have to (a) understand the strategies of each game they play, (b) consistently play according to those strategies, (c) stop when they are ahead, and (d) consistently apply strong, reliable psi.

Over the long term casino profits are predictably stable, but given that some psi effects are known to be genuine, in principle a good, consistent psychic (who knows how to play the casino games) might make some money by gambling. In addition, many people applying weak psi may cause small fluctuations in casino profits, but testing this would require analyzing an enormous amount of casino data, and such data is difficult to obtain.