A level (aka Star) Is an indication of how powerful The Monster card is , they are often placed in the top right of the monster card below the attributes, it is often yellow and orange, Monsters with level 1 to 4 are normal  summoned without costs, while monsters with level 5 to 6 require 1 tribute, wheras levels 7 or higher require tributes, however, level 9 or higher are rare, they can require an extra tribute depends on the effects of the card itself.

A level 3 Monsters usually do not exceed 1750 ATk, while  level 4 do not exceed 2000 ATK, while Level 6 do not exceed 2600ATK, Level 8 do not exceed 3000ATK, Level 10 do not exceed 4000ATK, and level 12 do not exceed 5000 ATK, however, some monsters those break these rules either they have negative effects or summoning conditions.