While Master Rule 6 (or the current "Revised Master Rule 2020/2025") remains the backbone, incorporates all the latest rulings regarding:
If a monster’s activation condition is met but its location changes before it can activate (e.g., it’s moved from the field to the hand mid-chain), its effect yugioh rulebook 20 pdf new
Understand exactly how Pendulum, Link, XYZ, Synchro, and Fusion monsters interact. While Master Rule 6 (or the current "Revised