The Creative Strategist
There is no perfect strategy that the human mind can conceive of, because the optimal strategy is different for every situation and there are too many variables to be accounted for. This guide is not comprehensive, it is merely my attempt at sharing some generalized knowledge I've picked up. The best strategists are the ones who are the most creative, who remain aware that it is impossible to predict all possibilities and pitfalls in a plan and so are able to adapt their strategies when the situation calls for it.
Early Game, Mid Game, and Endgame
The goal of the early game is to set up your economy in preparation for the coming battles.
The goal of the mid game is to destroy your enemies' economies. The mid game starts when players stop focusing on increasing their own economy and begin attacking other people's plants and oil rigs.
The goal of the end game is to destroy your enemies' bases. At this point one player or alliance will reign supreme on the server, having crushed their enemies' economies during the mid game. Now the final step is to eradicate the bases and surviving soldiers.
Nobody Ever Defended Anything Successfully
"Nobody ever defended anything successfully, there is only attack and attack and attack some more." George S. Patton
No defense will endure forever without an economy larger than your enemy's, and it is impossible to construct strong defenses around all of your plants and oil rigs. Constructing defenses is futile and wasteful. This strategy guide is only concerned with aggressive tactics.
How to Set Up Your Economy
Begin by constructing a power plant at the crystal near your command center. If it is a land map, construct power plants at your allies' bases if you have any and then continue building power plants at other crystals. If it's a water map and you are on an island, then you should build power plants at the crystals on your island and then focus on building oil rigs on all available oil, because it's the cheapest way to increase your income. If it's a water map with one main land mass, then you should immediately focus on building oil rigs before building more plants.
Power Plants vs Nuclear Plants: Which to use and when?
An important principle to remember when expanding your economy is that every time you build a plant, you are investing money. At first you lose money when you spend it on the plant but you expect to get it back. However, this takes time. It takes six minutes and thirty seconds for you to start profiting off of a power plant, and nine minutes and twenty seconds to start profiting off of a nuclear plant. Obviously, the nuclear plant will give you more income, but it will simply take longer and be more expensive. As with all things, this is situational. In the early game I would highly recommend only building power plants, but later on it may be a good idea to build nuclear plants as long as you are confident that the danger level is low enough so that they won't be destroyed before you can profit from your investment. However, with supercrystals you must always build a nuclear plant, it would be wasteful to do otherwise.
What to Sell and What to Use
After the early game you will want to get rid of your light soldiers and scout to have room for heavy soldiers. You can either sell them, or sacrifice them to try to cause a little strife for your enemy. Try going around and attacking plants with them if you can, they can outrun heavy soldiers and it might prompt your enemy to waste money by turret spamming which will help you in the long run.
Concerning your Command Center, selling it in the beginning can give you a helpful boost. Only do this if you are playing solo or don't depend on an ally's production buildings and you don't need to use it to protect any buildings like a barracks or soldier house. Using natural defenses instead of depending on your Command Center is a much better option.
On water maps where you use a construction soldier to place a shipyard, you should sell the construction yard when you can to make more space for other buildings later on.
Things You Should Never Buy
First and foremost, turrets. I'll go into detail about that in a moment. Don't build light soldiers or tanks, they are less cost effective compared to their heavy counterparts. Don't build shields. They are easily destroyed, very expensive, and we've already established that defenses will do you no good. Likewise, don't build walls, and only build forts if you plan to use them to produce units. Don't build headquarters, nukes, or bunkers.
Turret Spamming: Why you shouldn't do it
Every time you place a turret near a plant to protect it, you are essentially investing even more money into the plant, increasing the time it will take for it to pay off. Turrets are immobile, can be walked around, and can be destroyed from a distance. Turret spamming will be devastating for you in the long run.
Why Nukes are Worthless
Nukes are by far the most overrated thing in the game. They take an immense amount of time and money to build. At the bare minimum with one research center, it takes $1075 and twenty-eight minutes and thirty seconds to produce a single nuke, (roughly the length of an average game) which can't even destroy most buildings on its own. To put it into perspective, with $1075 you could produce eleven heavy tanks, or 53 heavy soldiers, more than enough to conquer the map.
Diplomacy, Truces, and Cross Teaming
There are two ways to choose your allies. The first is to team with whoever is nearest to you to gain economic and positional advantages. The second is to find the most experienced players on the server, judging by their skins, and teaming with them to instantly eliminate a potential threat and gain a valuable ally.
Sometimes a truce between alliances will be proposed, such as "No attacking until 15 minutes" or "No attacking each other's oil". If the enemy side proposes this it will give you a big advantage. Say that you agree to disarm them, then they won't be prepared when you backstab them.
Alliances occasionally team together to take down a larger threat or as a temporary truce until another enemy is destroyed. If there is someone more powerful than you, you should always cross team with a less powerful person so that you can match their power. If you form an alliance with the more powerful player, they will easily defeat you once the other threat is out of the way. Watch the balance of power and try to keep it in check.
Utilizing Natural Defenses
I've explained why defenses such as turrets and shields are a waste of resources. Natural defenses, however, cost you nothing and are much more effective than the defenses you have to buy. A natural defense is either a hill that soldiers can't climb or water. In later sections I'll explain landlocking and using water to your advantage, but for now we'll focus on hills. When building a plant, try to build it as close to a hill as possible. Once you're able to build on the hill, you can put buildings there and it will be very hard for your enemies to reach them. You can also access hills by building a construction yard at the bottom. Utilizing this strategy is useful not only for defending your home base but also particularly when invading islands.
How to Thwart Turret Spammers
It's usually easy to send your soldiers out of range of the turret protecting the plant, but still have them be in range to shoot at the plant. Inexperienced players often respond by wasting even more money, building turrets all around the plant. This is fine because it will only hurt them in the long run. Adding insult to injury by destroying their plant despite their best turret spamming efforts is a fun way to deal with an annoying strategy. You can also put down a plant at that crystal no matter how many turrets are there, because turrets only target units.
The Advantages of Snipers and Other Special Units
Snipers will greatly increase your army's efficiency against armies of heavy soldiers. I would recommend getting three if tanks are too expensive. Try to protect the snipers with the other units. You can position a sniper in range of enemy soldiers and kill them from a distance, especially if the enemy isn't paying attention. Jeeps and humvees are very useful because of their speed and extra defense. If you put snipers in them then you've created a mobile soldier mower. Juggernauts in humvees are very effective, especially on land maps, although the strategy isn't very common because in most maps and situations it would take too long to build. Putting a medic inside a jeep or humvee will create a single self healing unit, which you can use to attack your enemy and then retreat and heal when the health is low.
How to Make the Most Out of Every Soldier
When attacking, try to position your army to all fire on one target. An experienced player will do the same to you, so readjust your army throughout the battle to position your most wounded soldiers behind and out of range of the ones with the fullest health bars to retain firepower and last longer. If you do this enough you'll end up with a lot of heavily wounded soldiers, so it may be a good idea to heal, repair, sell, or sacrifice them and then build new ones.
Mirroring: a Strategy for Land Maps
The strategy is simple, you mirror your opponent's actions. If they build a barracks, you build a barracks. If they build a tank factory, you build a tank factory. When you're not mirroring their actions then you're building more power plants. So in theory, when they attack you, you'll have a bigger economy and have an advantage. It doesn't work quite so well with water maps, especially island ones, since the separation of land masses makes things more complicated, which will be covered in later sections.