Why play multiplayer when someone can just randomly declare war and send a stack of doom at you? 
It's no different from SP.

It's no different from SP.

Automate workers once a war starts (with no chop and no tearing down improvements)
Use stacked movement for armies whenever possible. Also use pathed movement on your way to the front
Use production Queues in your cities whenever possible. Set those queues on less active turns when you are waiting for others to finish. This lets you concentrate more on a war on less on random buildings going up around your empire.
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