This is probably so well-known it doesn’t really warrant a note, but just in case, the commit/reveal pattern is useful for many contracts.
In the context of prizes for solving puzzles, e.g. in Mathematical Fun with ErgoScript, it is best to require that a commitment to the solution is mined first before the solution is revealed. Without a commitment, revealing the solution in an unconfirmed transaction is vulnerable to theft because the solution can be copied into a new transaction, and the reward sent somewhere else, assuming it gets mined.