Crapless craps (also known as "ruse craps") offers players just what the name implies. On the come out roll you won't 'roll craps' if you roll a 2, 3, or 12. Instead of instantly losing your line bets, 2's, 3's, and 12's can become points. This isn't the only difference, but it is the only publicized difference. If the only difference between a standard craps game, and a game of crapless craps was this change then the house edge would be no more. The game would simply offer better odds to every player, and clearly casinos aren't racing to do this.
Too good be true?
Definitely. Crapless craps is just a marketing ploy to sucker players into losing bets. To compensate for this change with the 2's, 3's, and 12's, the casino also takes away your chance to win on the come out roll by rolling an 11. So now your come out roll either results in a point, or a win with a seven.
So it's three less chances to lose and one less to win. Still sounds pretty good, right? Lets take a look at the numbers. 2, 3, and 12 are pretty hard numbers to roll, and even if you hit one you haven't won, you've just continued with them as a point. After you do the math, a pass line bet in a crapless game carries a house edge of 5.4%. Compare this to the pass line bet in a standard craps game which only has a house edge of 1.41% and it should be clear which table is offering you the best deal.
Another big change (though it doesn't affect right bettors) is that there are no don't pass line bets in crapless craps, but considering the other changes this does make a good bit of sense.
Just like with a standard game of craps you can play with (fair) odds bets to improve the house odds on your pass line bets. However the odds bets are still fair odds (payout the same as normal odds bets) so they still aren't competitive with odds bets in a standard craps game. For the 2, 3, and 12 that couldn't normally be points (and there for have odds bets) 2 and 12 both payout 6 to 1, and the three pays 3 to 1.
In summary even if a game of crapless craps sounds like a steal after you tried to crunch the numbers in a busy casino after a few stiff drinks, remember what you read here, and save yourself the grief in the future.