Plate letters: BRT
Possible words: BRIGHT, BIRTH, BRACKET. BIRTH works because B comes before R and R before T.
Inspiration
WordSQD grew from a car game: see three letters on a license plate, then find the best word that uses those letters in order.
Take three letters from a license plate and find a word containing those letters in the same order. The letters may have other letters between them.
Possible words: BRIGHT, BIRTH, BRACKET. BIRTH works because B comes before R and R before T.
Possible words: LAMP, LIMP, LAMPSHADE. The letters can be consecutive or spread out.
Possible words: ROAST, RESIST, RESTART. STAR fails because S appears before R.
Three letters define a left-to-right path through the answer. A candidate can contain all three and still fail if one appears too early.
WordSQD adds a timer, server validation, difficulty multipliers, Forbidden mode, challenge links, saved games, and the Daily board. Those fixed rules make results comparable across browsers and players.