Bluffing into a Dry Side Pot

If you play online poker tournaments, or live tournaments, sometimes you'll have one player all-in while others in the pot still have money left to bet. Any additional betting goes into a side pot, and the all-in player is not eligible to win that pot. Suppose players A, B, and C are in a pot together. A and B start with 1,000 chips and C starts with 100. All of C's chips go into the middle before the flop, so C is all-in and there is no money in the side pot.

A and B are the only ones who can bet, and they check the flop and the turn. On the river, A has a dreadful hand – he can't even beat the five cards that are on the board. A bluffing here is a horrible play. At best, B will fold, but C can't fold because she already is all-in. Since A has a horrible hand, C will win and collect the pot. A is risking being called by B and losing, when there is no way to benefit by betting.