Use the recon option before attacking other players to find out if they have resources that you need. Upgrade your recon through the research laboratory to get more details from it. You can also spy on what they have on their walls as well as troops used in their defenses. However, recon has no benefit if your target is infected. In this situation, rely on the current level of the opposing player to decide whether to attack. Upon clearing an infected city, it will turn into a deserted city without any defense or other units. A deserted city will have all five resource types that you can farm. Select opponents based whether they have useful resources and if their defenses can be overrun by your forces. Infantry is strong against demolitions, demolitions are strong against vehicles, and vehicles are strong against infantry. This type of hierarchy means that battles are usually won by the side that has the most number of units. Include each of those troop types to give yourself an advantage against all defenders.
