&gt; <i>You could use this model of recording inputs and playing them back on the server but that seems like it would be a ton of work if your game is popular and an extraordinary cost for keeping a simple score board clean.</i><p>You only need to validate scores that would actually make it onto the leaderboard, which would be a tiny fraction of all plays. To avoid being overwhelmed by bad submissions, you flag users who send them as &quot;don&#x27;t even bother checking, just log and reject&quot;.<p>The real problem is RNG manipulation and TAS-ing in general. How do you to ensure a malicious user automatically can&#x27;t brute force the whole tree of possible plays?