D'karr
Adventurer
Actually the DMG specifically calls this type of action out as totally available to the DM (See DMG pg. 38 Roll Initiative Section). Monsters can ready within their turn without shifting their order in the initiative. So two monsters with the same initiative number can move and ready to attack when they are flanking.
I wouldn't do this for mindless creatures as such, but creatures that would naturally understand tactics should use them.
I wouldn't do this for mindless creatures as such, but creatures that would naturally understand tactics should use them.