The main goal in craps is to roll your number ("the point") before rolling a 7. Since there are different ways to make different numbers, the odds of this change depending on the point. Your odds of rolling a 4 or 10 before a 7 are 2-to-1 against, of rolling a 5 or 9 are 3-to-2 against and of rolling a 6 or 8, 6-to-5 against
This is important to know because in craps, you have the option of taking "true odds" behind your initial bet. What this means is that your original pass line bet is paid off at even money, which gives the house an edge. However, your back bet of true odds get paid off at the actual odds of rolling that number, which means no house edge on that bet.
Odds on Other Bets
The bets on the layout besides pass, come, don't and individual numbers tend to offer a high house edge. For example, your true odds of rolling a hard six or eight are 10-to-1, but pay off at 9-to-1. A hard four or ten is 8-to-1 against, but you get paid 7-to-1. Worse are one roll bets. You get paid 30-to-1 for rolling a two on the next roll, but the true odds are 35-to-1, for a house edge of nearly 14 percent.
Deciding What to Bet
It should be clear that the best bets to take in online craps are the pass/come, don't pass/don't come, for which the house edge is less than 1.5 percent. Buying individual numbers offers a relatively low house edge as well.