If a casino triples the 2 and 12, it is an even proposition.

36 combinations of the dice - 6x6

16 are in the field
2 - 1 way to make it
3 - 2 ways to make it
4 - 3 ways to make it
9 - 4 ways to make it
10 - 3 ways to make it
11 - 2 ways to make it
12 - 1 way to make it

20 are out of the field
5 - 4 ways to make it
6 - 5 ways to make it
7 - 6 ways to make it
8 - 5 ways to make it

So the odds of hitting a field number are 16/36 or 4/9 or about 44.45%

The odds of missing a field number are 20/36 or 5/9 or about 55.55%

The payoff is another story. If we only paid even money for any number hit, we would have a 16 - 20 pay out. Out of the 36 combinations, I pay you 16 units and take 20 units away from you.

If we paid double on the 2 and 12, like most casinos do, we would have a 18 - 20 pay out. Out of the 36 combinations, I pay you 18 units (this assumes you hit each combination of the dice, hitting the 2 and 12 only once) and take 20 units away from you.

If we only paid double on the 2 (or 12) and triple on the 12 (or 2), we would have a 19 - 20 pay out. Out of the 36 combinations, I pay you 19 units and take 20 units away from you.

If we only paid triple on the 2 and 12, we would have a 20 - 20 pay out. Out of the 36 combinations, I pay you 20 units and take 20 units away from you. An even proposition.

I'm not saying no casino would do it. Mathematically, the casino does not make any money on odds either. I know players that play big money, that play heavy odds (we have 20x where I work, had 100x for years), but only get rated on the flat bets they make, but that is another post......