* Before declaring an attack: You can activate effects that respond to the opponent's monsters being in attack position, or effects that can trigger before the attack declaration.
* During the Damage Step: You can activate effects that trigger when a monster inflicts battle damage, or effects that can be activated in response to battle damage being dealt.
However, there are some important things to remember:
* Effect timing: Many card effects have specific timing restrictions, such as "during your Main Phase," or "when your opponent summons a monster." Make sure to read the effect text carefully to see when you can activate it.
* Chain effects: If you activate a card effect, your opponent may be able to activate a chain effect in response. This can lead to a chain of effects being activated, and the outcome of the battle can change dramatically.
* Continuous effects: Some card effects are continuous effects, which means they are active for the entire duration of the game. These effects do not have specific timing restrictions and can remain active during the Battle Phase.
It is important to note that:
* You cannot activate card effects during the Damage Calculation portion of the Battle Step.
* You cannot activate card effects during the End of Battle Step, which occurs after both players have declared attacks and any damage has been inflicted.
By understanding the timing and restrictions of card effects, you can maximize your chances of winning in Yu-Gi-Oh!