Replays

Ok, so Replays aren't a new thing in the game, they just weren't as common before Zexal and 5D's.

A replay occurs when 1 of 3 conditions are met:

1) The attack target is removed from the field by a card effect

2) A new monster is summoned to the field before the damage step by a card effect

3) The number of monsters on the defender's side changes by a card effect

Obviously, a Replay can only occur during the battle phase and when a replay occurs, you chose to either attack again or not attack at all. If you attack with a different monster than the one that was originally involved in the Replay, you cannot attack with the original monster as it is considered to have already declared an attack. Additionally, Replays don't give your monsters a second attack, they just change the target so if a replay occurs, cards like Mirror Force can't be activated as they miss the timing due to the replay occurring first.

So let's explain some situations where a Replay occurs.

1) The attack target is removed from the field by a card effect

You have "Number 39: Utopia" on the field and you attack your opponent's "Masked HERO Dark Law" but your opponent activates their "Interdimensional Matter Transporter" and removes "Dark Law" from the field. Since "Dark Law" is no longer on the field, you can choose to have "Utopia" attack another monster your opponent controls (if they have any) or attack directly.

The activation of "Interdimensional Matter Transporter" causes a Replay to occur. This means that trap cards like "Mirror Force" or "Dimensional Prison" can not be activated because they miss the timing. In order for either to be activated they have to be Chain Link 1 (the first card activated in the chain). Neither of them are. Chain Link 1 in this case would be "Interdimensional Matter Transporter" forcing "Mirror Force" or "Dimensional Prison" to be Chain Link 2 and therefore, miss the timing. Both cards state "When an opponent's monster declares an attack..." which means that they must be activated in response to an attack first.

Furthermore, you must attack with "Utopia" first if you choose to, but this attack is not considered to be a new attack declaration, it is simply changing the target. If "Utopia" does not attack first when the Replay occurs, it is considered to have already declared an attack and can not attack again this Battle Phase.

2) A new monster is summoned to the field before the Damage Step by a card effect

This is very similar to condition 3, but there is a difference. You control a "Gemini Elf" and you attack your opponent's "Elemental HERO Shadow Mist" with your "Gemini Elf". Your opponent activates their "Mask Change" Quick-Play Spell Card and uses "Shadow Mist" to summon "Masked HERO Dark Law". In this instance, the number of monsters on the field hasn't changed at all, but "Dark Law" is replacing"Shadow Mist" as a new monster and so a Replay occurs.

As with condition 1, "Gemini Elf" must be the first monster to attack if you choose to continue your attack, but you can only switch your attack to a new monster OR you can continue to attack and target "Dark Law" (although you wouldn't because "Gemini Elf" would be destroyed, but you might want that to happen for whatever reason). You can also choose to not attack at all.

A similar thing happens with monsters that can special summon themselves, such as "Guardian Dreadscythe" or "Colossal Fighter", but are not considered Replays. Say "Guardian Dreadscythe" attacks your opponent directly, but they activate "Mirror Force" and destroy "Dreadscythe". You then must summon "Dreadscythe" (because it is a compulsory effect. This will be explained in later posts) back to the field. At that point, "Guardian Dreadscythe" is a considered to be a new monster and so can declare an attack, even though it attacked previously and was destroyed. The same applies to "Colossal Fighter"

3) The number of monsters on the defender's side changes by a card effect

This will be a simple one. You control "Dark Magician" and your opponent controls no monsters. You attack directly with "Dark Magician" but your opponent activates "Scapegoat" and summons 4 tokens to the field. Now your "Dark Magician" can not attack your opponent directly as there are tokens in the way and so you must choose to target a token instead, or not attack at all.

I hope that information clears some things up about Replays for you guys because they can get confusing at times. I'm working on another University Assignment, but I will post again when I can.