Once You have chosen Even or odd you must stay with that throughout the battle.
All attacks related has same reason.
Final Fantasy Dice Go to Keyword Dice. To make 50 you must type it in the white box at the bottom of the window. In battle it is accentual to use dice, everyone must use 50 - 100 for dice. One person will roll to determine who will go first. One person must pick odd or even before the dice is rolled.