Rewarded video and interstitial ads are both full-screen formats, but they part ways on one crucial point: consent. A rewarded video is something the user actively chooses to watch in exchange for a benefit; an interstitial simply appears when a trigger fires, whether the user wants it or not.
How the two formats differ
Rewarded video is opt-in by design — a player taps a button to unlock an extra life, in-game currency, or a piece of content, and only then does the ad play. Interstitials don't ask permission; they're tied to an event like a level completion or screen transition, and the user has no say in whether one appears.
That one difference changes almost everything else about how each format behaves: completion rates, perceived intrusiveness, and how publishers need to think about frequency.
Revenue and UX tradeoffs
Because the user opts in, rewarded video usually sees very high completion rates and close to zero negative sentiment — nobody complains about an ad they asked for. Interstitials reach a much larger share of a session automatically, which can mean more total impressions, but at a higher risk of frustrating users who didn't ask to see one.
Most mobile games end up running both: rewarded video as a value-exchange option players can seek out, and interstitials, carefully capped, at natural break points.