Ranked 2v2 play continues to be an under-appreciated aspect of Starcraft 2 play. Part of the reason for this is due to the fact that Starcraft 2 is not really balanced for a longer 2v2 strategy game. In fact, I would argue that it is almost impossible to balance both 1v1 and 2v2 matches in order to encourage longer macro games.
Lets do the math for a second. The total number of races is 3, each one of those races can be played as a team, ZZ - TT - PP (3 combinations), and each team can play against itself or others (ZZ v. ZZ, ZZ v. TT, ZZ v. PP, etc.). This makes a total of 6 team combinations to balance without consideration for mixed teams. To make matters worse, you also have to apply all of your balance tweaks to 1v1 matches. When you start to crunch the numbers, the total number of combinations that you have to account for when balancing is dizzying.
This general imbalance can result in some serious domination by teams savvy in the ways of 2v2 cheese. Nevertheless, despite the imbalances, 2v2 play can also be the source of a lot of fun. A budding 2v2 match team need only be aware of a few strategy principles in order to survive the fray. Here is what I have learned after clawing my way to the Diamond league with 2 separate teammates.
Tips after the jump.
1. Coordinate with your teammates over voice communication
A substantial portion of team match players are not on a team. These players are sifted through random selection and meet their teammate at about the same time you meet them as opponents. As a result, a well coordinated team over voice communication has a substantial advantage over a non-communicating team by virtue of being organized. Coordinated attacks and retreats can easily turn the tide of battle.
This principle also applies to the planning phase of the match. For example, you can choose a build order that complements your teammate nicely. Adding more marines to your mix as a Terran player would complement a zealot heavy build because the zealots can tank damage while marines pour on the DPS.
2. Know your cheese
I won't harp on the imbalance point any further but I will add that you can at least mitigate the effects of a cheese build if you scout it early. I would encourage you to try them out as well because they can be a lot of fun. There are plenty of interesting all-in cheeses that are out there but here are a few that I personally know of.
The Korean 5-Gate 24 Speedling Rush - Essentially involves harvesting the power of the Korean 4-Gate and coupling it with the speed of a speedling rush. Check out this link for the build.
6 Pool SCV All-in - Several variations of this build are out there but the general principle consists of a 6 pool on behalf of the Zerg player and as soon as his lings pop, the teammate sends out several SCV's to help kill off an opponent. This build also requires a map where the opponents are isolated.
Standard rushes - Standard rushes can be twice as effective in a 2v2 match due to the possibility of isolating an opponent. A fairly standard rush that has put one of my teams (Double Protoss) into the Diamond league is the standard Protoss 2 Gate -- times two of course. Although we leave plenty of room to transition out of the build should the map or opponent races not be favorable, it is still highly effective. Look for early marine/2 gate rushes, early marine/ling, and double 6 pools as well.
3. Scout Early and Often
This principle is really a corollary from the last tip. Considering the high incentive for rushes and cheese builds, make sure you scout your opponents -- and your own base -- for any funny business. A good practice is to place your supply buildings/overlords around your base to have line of sight over most, if not all, of your base.
The general rule of thumb is that if you don't understand a particular build that your opponent is executing early-on, a red flag should be raised.
4. Map Awareness
Knowing how to read maps and map positions is an art in it of itself but you can get started by keeping a few ideas in mind.
First, notice if you and your teammate are considerably isolated from each other. Arid Wastes would be an example of a wide gap between teammates. If you are separated, do everything you can to take advantage of this (attack one opponent quickly and together) and to protect yourself from being double teamed by your opponents. For example, say your match has been set up in Arid Wastes against 2 Zerg opponents. In this scenario I would take immediate steps to mitigate the effects of a double 6 pool just in case it happens. You can scout extra early, push out units early, or just wall off earlier than normal.
Second, some maps favor an early expansion. Although I highly recommend against early expos, it seems to work for some players and you should consider doing a Forge Fast Expand or Planetary Fortress early expo while your opponent defends. On the other hand, if you see a map that does favor an early expo try to scout it and put pressure early. This will usually lead to a very early win.
Maps almost always guide my decision making in the first 10 minutes of any match. Be aware of the maps that favor/disfavor your particular style of play and accommodate.