Consider this. Let players change their decks for Day 2 of Worlds. Here's my reasoning: 1. Meta-gaming is a scouting skill. Meta-gaming for Day 1 is a bit of a guessing game. Meta-gaming for Day 2 can only happen if players are allowed to change their decks. 2. If Day 2 of Worlds is the Playoffs, and the rumor about best-of-3 for the Playoffs at Worlds is true (assuming the Swiss rounds will be 1-game matches), then players can change/enhance their decks to perform better for multi-game matches. Just an idea that I'm taking from how Lord of the Rings Premier events are run.