Depende do acionador da ação preparada DDI .
Como já foi esclarecido no Manual do Jogador página 291 ...
Interrupting an Enemy: If you want to use a readied action to attack before an enemy attacks, you should ready your action in response to the enemy’s movement. That way your attack will be triggered by a portion of the enemy’s move, and you will interrupt it and attack first. If you ready an action to be triggered by an enemy attack, your readied action will occur as a reaction to that attack, so you’ll attack after the enemy. Note that an enemy might use a power that lets it move and then attack. If you readied an action to attack in response to that enemy’s movement, your readied action interrupts the movement, and you can attack before the enemy does.
Carga é movimento, depois ataque. Ao ajustar o seu gatilho na parte do movimento ( "assim que um inimigo estiver ao alcance" ) você é capaz de usar uma reação imediata para acertar o monstro atacante antes do ataque do mago.