During the two weeks prior to a set releasing, local game stores will host prerelease events, allowing players to obtain cards from the set before the packs hit retail shelves. During a Prerelease event, all players are given a Build and Battle Kit. These products contain 1 of 4 different ready-to-play 40 card decks alongside 4 Booster Packs, which can be used to modify the deck prior to a tournament in which all players use their provided decks.

Typically, these events are casual affairs in which all tournament participants reveive additional packs at the end of the event. However, some stores will instead use the tournament results to influence prizing. To match the 40 card decks, games are played with 4 prizes instead of the usual 6.

The Build and Battle Kit does not come with Card Sleeves. You will need to have 40 of them to sleeve your deck and play in the event. You'll also want some dice for damage counters.

Prerelease decks play much differently than decks in the Standard format. With limited access to powerful Supporters and Items, many games will come down to one player setting up while the other player struggles to find their most important cards. Follow these tips when upgrading your deck:

- If you pull a Trainer card that benefits your deck, you'll almost always want to include it.

- Look for Basic Pokémon with attacks that draw or search cards, like "Collect" or "Call for Family".

- When your deck contains multiple types, it's a good idea to count the Energy cost of your 4 best attackers and include Energy in a ratio that reflects them. For example, with 2 [G][C][C] and 2 [R][R] attackers, you'll want to include twice as many Fire Energy as you do Grass. You'll also want to make sure you have at least 10 Energy, exactly enough to power up all 4 attackers; however, it's probably a good idea to have at least 12, allowing you to see them more consistently and providing leeway to Retreat or use supporting attacks like Call for Family.

- If you pull a particularly powerful Basic ex or Basic Mega Evolution ex, it may be worth running it alongside 39 basic energy. Your opponent will draw many cards from the Mulligans you take, but you're guaranteed to open the Pokémon you need every single game.