So if my opponent and I both play an Order delay card, but I do 100 delay moves before I play the card, and he plays 100 delay moves after he plays the card, and we both attack, which attack is later?

see Krunx 's post.

Edited 8/22/2018 14:21:07

OD ==> infinite number of turns.

==> What happens before the OD-card is only relevant for the 1st move after the OD card.

In your case:
Your opponent's attack is later.

If you make 100 moves, then play the delay card and then make 1 attack you'll move before your opponent who plays an OD card first and then makes 100 moves and then 1 attack.

First all moves before delay cards are made -> The delay cards are played -> Move order continues like it did after that if both parties played an OD card so you'll attack before him.

^ This

Min said it well

Move order continues like it did after that if both parties played an OD card

Not completely true, read this thread: https://www.warzone.com/Forum/152388-move-order

Interesting read.

Here's how it works, for each phase:

1. Consider all players with unprocessed orders. Is the top order for everyone an Order Delay card? If so, process one OD card from everyone.
2. Process the top order from each player whose top order is not an order delay card.
3. Reverse the move order.
4. If there are still unprocessed orders, go to 1.

https://www.warlight.net/MultiPlayer?GameID=11157247 Turn 7.

The attack phase begins to process. Sultan has first move, Njord has second. First, we check if all player's first order is an Order Delay card. They aren't.

Now we process one order for each player. Sultan's first order is an Order Delay card, so he's skipped. Njord's first order is the attack from Kenya's so it's processed and removed from his pending orders list.

Move order reverses. Now Njord is first, Sultan second.

Both players top order is an OD card, so we process both of them.

Now we process one attack from everyone. Njord is first in the move order, so his transfer to Hong Kong goes first.

Seems to be the important part on how it works.