Have all of your industry types collected in one area so a friend can invade for the resources he/she needs. Have no defending units around.

When your friend invades (or you invade your friend who should be following steps 1 & 2 as well) make sure they only use max two units to defeat the two units that you get to defend for free.

Victory will be easy and you leave your friend a weak army to right when he repels the invasion. Also notice that a battle with fewer units will use less energy.

It’s a good idea to include a message.

After your friend is victorious (and without losing many military units because defense was so light) and collects cash, goods and infamy, you can then repel the invasion which will be very easy to do because your friend used a minimum level of units. You also should lose minimum units in the defense because the invading force is so light. You then collect the rewards of defending.

If you want to maximize this technique, part of your empire should appear similar to this on the right. Notice the way each resource is grouped together and has no units defending them to allow an invader to select the resource they prefer. Educate your friends on this method of playing so they will reciprocate.

More about Empires & Allies click here