Many proposed blockchain solutions use verification games, whether informally as in TrueBit and Plasma, or formally as in Alacris.io. In these systems, an important challenge is for the contract to be able to assess whether participants are putting down sufficient collateral to accompany their claims; and this assessment crucially depends on having a good model for the price of gas.
In a system based on verification games, participants make claims that others may disprove if they are invalid. Each step of the verification game (or “smart lawsuit”) happens by invoking the “smart contract” on the blockchain with parameters detailing the claim (making a “smart legal argument”). If no one successfully counters the claim with a counter-claim within its challenge period, then the claim is considered validated. To punish those who make spurious claims and reward those that prove their claims invalid, participants who make a claim must accompany it with the deposit of a proper collateral. The collateral will be released back to the claimant if the claim is validated, or to the counter-claimant if the claim is invalidated.