Level 4 ATK and DEF conventions

The "Rule of 2000" is a general rule that previously applied to Level 4 or lower Monster Cards, until the release of Gene-Warped Warwolf in Strike of Neos. The "Rule of 2000" stated that once Monster Cards got to 1900 ATK, to go further, to 2000 and beyond, Special Conditions had to apply to the monster to limit the card.

However, DEF does not have a "Rule of 2000", instead, it has a "Rule of 3000"; 2000 DEF Monster Cards are plentiful, and many Level 4 or lower Monster Cards are higher than 2000 DEF. Some monsters have 2100 DEF that are level 4 or less.