The oil-and-gas leases at issue state that interest will accrue on past due royalties "at the maximum rate allowed by law." The Supreme Court ruled that this falls under Texas Finance Code section 304.002, which says that when a contract provides for interest, a judgment on that contract will accrue post-judgment interest at the lesser of 18% or the rate specified in the contract. The Court held that the post-judgment interest rate on the past due royalties in that case was 18%, since that was the "maximum rate allowed by law."But the Court also addressed other contract damages for which the leases did not state an interest rate.