How to build a Pokémon master set

Short answer: a master set is every card in a set, including every secret rare and every reverse-holo version. A "base set" is just the numbered cards up to the printed total.

Plan it

1. Pick one set you love — the art matters more than anything.
2. Print or open its chase checklist and tick off what you have.
3. Finish the commons and uncommons first by trading with friends.
4. Save the chase cards for last and trade duplicates for them.
5. Store everything in a side-loading binder as you go.

The biggest sets to master

Ascended Heroes (295 cards) · Fusion Strike (284 cards) · Paldea Evolved (279 cards) · Cosmic Eclipse (272 cards) · Paradox Rift (266 cards)