Size is an attribute of Monsters. There are three sizes present in the world of Ragnarok Online:

• Large (Big)
• Medium
• Small

Human playable character are by default, Medium sized when engaging each other in a PvP environment. However, if a character is adopted, they are considered Small sized. Doram playable character are considered Small sized.

Most weapons suffer size-penalties against certain sizes, although it is only minor when looking at damage on a grand scale.

Some equipment or card can nullify weapon size penalty.

• +11 Infinity Blade [1]

• Ally of the Demons [1] (If Gentle Touch-Convert is level 5)

• +11 Drakes Coat [1]

• +13 Bear Aimed Bag [1]
• +13 Melody Wing [1]

• Chaser's Shoes [1] (If Feint Bomb is level 10)
• Sniping Shoes [1] (If Aimed Bolt is level 10)

• Drake Card

• Biolab Gemini Crown [1] + Zodiac Boots(Thief) [1] + Eremes's Memory (If the sum of helmet, shoes, and weapon refinement level is 35 or higher)

• +10 Infinity Shadow Weapon
• +10 Infinity Shadow Shield

• Mistress Egg (When intimacy is Loyal)

• Shield Reduction Cards by Size
• Weapon Cards by Size