A battle position, known as an display mode (表示形式, Hyōji Keishiki) in the Japanese version, is a position in which a monster is placed to determine how it behaves in battle. The two battle positions are Attack Position and Defense Position.
Attack Position monsters are placed vertically on the field, while Defense Position monsters are placed horizontally.
Attack Position monsters are able to declare attacks. If two Attack Position monsters battle, the monster with lower ATK is destroyed and its controller loses Life Points equal to the difference in ATK. If an Attack Position monster battles a Defense Position monster with a DEF greater than the attacking monster's ATK, neither monster is destroyed. However, the attacking player loses Life Points equal to the difference between the ATK and DEF. If a Defense Position monster is attacked, its controller does not lose Life Points.