Grill the game idea

Interview the user relentlessly about every aspect of the game they want to make until you reach a shared, build-ready understanding. Walk down each branch of the design tree, resolving dependencies between decisions one-by-one.

Ask the questions one at a time, waiting for the answer before continuing — multiple questions at once is bewildering. For each question, provide your recommended answer and why — the user should be able to say "yes, that" and move on.

Facts vs decisions: if a fact can be found by exploring an existing project or codebase, look it up instead of asking. The decisions are the user's — put each one to them and wait; never answer your own question and move on.