The Field Bet is one of the popular bets in craps at online casinos. It wins if certain totals are rolled and loses if other totals are rolled. The calculation of the house edge has some interesting dimensions. But before starting the discussion on the house edge it is essential to understand some basic features of the Field Bet.

One important feature of any bet in online craps is to understand when that bet can be placed. Here the Field Bet poses no problems. It can be placed before any roll of the dice. It does not matter if the roll is a come out roll or it is a roll after the point is established. The second feature to understand is when the bet pays out. Here again the Field Bet is very simple. The Field Bet is decided a single roll and is not carried forward. The third point to know is where the online craps bet is placed on the screen layout. The Field Bet is placed in the Field Box, which is an area with the text “FIELD” marked in it. The more important issue is when the Field Bet wins. The Field Box has the numbers 2, 3, 4, 9, 10, 11 and 12 marked in it. If the total rolled is any of these numbers then the Field Bet wins, otherwise it loses.

The calculation of the house edge for the Field Bet is complicated by the fact that the payouts differ for the different totals on which the Field Bet wins. Therefore the mathematical expectations have to be calculated for each payout separately and then added. This is demonstrated below for a wager of 1 unit.

Case 1: Totals of 5, 6, 7 and 8

Outcome: Field Bet loses

Number of ways of achieving outcome: 20

Total number of combinations that can be rolled: 36

Probability of outcome: 20/36

Loss (-)/Gain(+): -1

Expectation: -1*(20/36) = -0.556

Case 2: Totals of 3, 4, 9, 10 and 11

Outcome: Field Bet pays 1 to 1

Number of ways of achieving outcome: 14

Total number of combinations that can be rolled: 36

Probability of outcome: 14/36

Loss (-)/Gain(+): +1

Expectation: +1*(14/36) = +0.389

Case 3: Total of 2

Outcome: Field Bet pays 2 to 1

Number of ways of achieving outcome: 1

Total number of combinations that can be rolled: 36

Probability of outcome: 1/36

Loss (-)/Gain(+): +2

Expectation: +2*(1/36) = +0.056

Case 4: Total of 12

Outcome: Field Bet pays 3 to 1

Number of ways of achieving outcome: 1

Total number of combinations that can be rolled: 36

Probability of outcome: 1/36

Loss (-)/Gain(+): +3

Expectation: +3*(1/36) = +0.083

Total expectation over all cases = -0.556 + 0.389 + 0.056 + 0.083 = -0.028

House edge = 2.8%

This house edge is about the same as that offered in European Roulette. The outside bets in online roulette also have payouts of the same order. Therefore players who have no problems with the outside bets in European Roulette should find the Field Bet acceptable. There are some online casinos that offer a payout of only 2 to 1 on a total of 12. This increases the house edge of the Field Bet to 5.6%, which is about the same for American Roulette. Online casino players must check out the payouts offered very carefully before wagering on the Field Bet.