One of the more entertaining things about multiplayer games is that you can ally yourself with other players for the length of the mission. The ability to use troops from both armies and combine your tactics allows for some truly interesting and esoteric possibilities, as well as some really dirty tricks.

Tricks with an allied partner range from the simple to the extremely complex. For instance, in most games, you can place your structures next to the structures of your allies. Early in the mission, ally with another player who's using the opposite army (if you're playing Allied, ally yourself with a Soviet player). Each of you builds an additional Barracks and places it in the center of the other player's base. Then, break the alliance and capture each other's Barracks. When you have both done this, re-create the alliance. Now both of you can produce both types of infantry. You can do the same with a War Factory, and even a Construction Yard, when both of you have created MCVs. This allows both of you to create such interesting possibilities as Tesla IFVs.

Once you've used the tactic above, break the alliance again and allow Spies to infiltrate each other's Battle Lab. This gives both of you an additional powerful unit (specifically, a Yuri and a Chrono Ivan).

The ability to build structures near allied structures allows for some additional interesting possibilities, as well. You can agree to place all of your special weapons in the same base, allowing both of you to group your base defenses to keep all of your special weapons protected by a mass of firepower. This does make them more vulnerable to a powerful attack, but the ability to group defensive structures from both armies together makes for a very powerful set of defenses to crack.

You should know by now how difficult it is to deal with units that have been Iron Curtained. You should also know that chronoed units can cause a headache, as well. So why not combine these actions? One player uses the Chronosphere to transport a group of units into an enemy base. Once inside, the other player should use the Iron Curtain on the Chrono team and they'll have at least a little time to cause some real havoc before the effects of the Iron Curtain wear off.