Advanced · Advanced · 6 rounds · ~8 min · free with an account
Output Formatting Secrets
Schema enforcement, prefilling, XML tags — the production tricks vendors don't teach.
Prompt Arcade · 6 rounds · free with an account
Output Formatting Secrets
For outputs a program will read, be strict: a schema, exact keys, no extra text, and a fallback for missing data. Show the shape, don't describe it.
- Build it
- Spot it
- Match it
- Order it
- Spot it
- Build it
Five games are open to everyone — start with Prompting Mindset 101. The other 31 need a free account (no card) so your scores and progress are saved.
What you'll learn
- Machine-readable output: Show the exact shape and ban everything else.
- Schema problems: Specify types and exact key names; show an example.
- Missing data: Always say what to output when data is missing — null is safest.
- Format block for code: JSON only → example → types → missing-data rule.
- Prefill and tags: Prefill the opening and use tags to extract reliably.
- Lists of items: Pick the format your code reads natively.
More advanced games
Self-Consistency VotingRun the same prompt 3-5 times → take the majority answer. +12-18% accuracy on reasoning tasks (Wang et al. 2022).Few-Shot Pattern RecognitionShow 2-4 examples → the model maps the relational structure, not the surface details (Chase & Simon's chess masters, applied).Constraint CalibrationToo few constraints → drift. Too many → brittle. The 5-constraint sweet spot and how to find it.