Bring a flint or bring a steel.

A strike runs fifteen minutes and both piles sit in the open the whole time. At the bell the piles are weighed. Only pairs make fire, so the lighter pile is matched in full: it comes back whole and takes the heavier pile's share of the fire. The heavier pile is matched only as far as the lighter one reaches. Its spare never meets a pair. It burns.

One thing a wallet a strike, from 1,500 $FLINTARD. The house keeps three in a hundred of the fire. Every rule.