This strategy depends on what type of game you are playing. An ACU rush can be very dangerous so you want to ensure your allies know what you are doing and can support your ACU or keep the enemies distracted.
What you want to do is focus all your research into your ACU upgrading health, weapons and shields. You want to get the most effective upgrades possible and so before you decide upon this strategy you should do some pre-game analysis of your tech tree to decide upon which initial research will be best for you and so you are familiar with the ACU research tree.
There is no single best way to handle your build order for an ACU rush, but it is imperative that most of your resources go into research stations. Most players start by building:
- 3 or 4 Research Stations with the commander, who upon completing them immediately begins moving towards the enemy position.
- Capture all nearby mass points with your engineers, but make sure one engineer accompanies your commander to assist and repair him.
- Build 6-8 power plants with the engineer remaining in your base and then begin spamming more research stations asap. The power plants will be essential in powering your Overcharge and Nanites (if Illuminate) later on.
- Do not spend any of your research points right away. Make sure you hold them in reserve until they are needed. This allows you to choose the best upgrades for whatever situation you find your commander in. Note that 9/10 times, you will want to go straight for Overcharge. The exceptions to this mainly involve being assaulted by bombers or gunships early on, in which case you may find the commander AA to be a good first stop.
- This strategy will probably not work best if your opponent is focusing on a large air army. This strategy will work best if you plan to attack early.
- It is a good idea to keep a couple engineers with your ACU to heal your ACU as you engage the enemy, or you can have one of your allies' ACUs heal your ACU as you engage the enemy.
- If your enemies are going for an early land rush, your ACU can be very effective in countering this if you micro it properly and ensure it has support from units like engineers who can repair it during the first engagement.
- Another sneaky idea is to build an air transport and transport your ACU along with a few engineers into the rear of the enemies base, taking out key infastructure.
- And unfortunate side effect of an ACU rush is that it leaves your base almost completely helpless with just a single engineer early on and a handful of research stations and mass points. Losing this base can cost you the game, but turning the commander back to defend it is usually impossible (unless you have jumpjets or teleport already). The best way to deal with losing your base is to press the attack and try and capture/destroy the enemy's base as well. Trading starting spots is sometimes considered to be an effective counter to the com rush (it at least buys the enemy some extra time if they were unprepared).
- The key to a successful ACU rush would be intel.. Build radars every so often as you advance. This not only provides intel to your commander, but also will provide warning if the enemy slips by your ACU and heads to your undefended base.
- If you are playing on a 3v3 or 4v4 map, it is best to avoid ACU rushing altogether unless multiple players plan to ACU rush together. Multiple ACU's rushing and repairing each other are exponentially more difficult to counter, and the enemy will find that unless they band together to take them out, they will be picked off one by one with little chance for resistance.
- If you find yourself being ACU rushed very early in the game, the key to surviving lies almost entirely on knowing it's coming. This means that in every single game, getting a radar or early scout plane out is priority #1.
- If you spot what appears to be a commander heading your way, you will want to immediately identify any chokepoints he must pass through (if any) and immediately place a factory at the chokepoint. Get the shield on the factory and begin placing point defense next to the factory so once the shield is built, the PD will be under the shield. Just 1 to 2 PD set up like this can completely repel an enemy ACU rush early on. Note that once the commander has tactical missiles, they can stand out of PD range and bombard your base with missiles, so it is best to not rely entirely on this plan, but it can hold off the ACU long enough for you to get a true counter together.
- Another option is to get early gunships and then attack the enemy commander directly with them. If you get enough of them out quickly enough, you can prevent him from being able to build AA, and either drive him into the water of kill him outright. Bombers can work in a pinch but are far more likely to get shot down by AA due to the time their sweeping passes take to execute.
- If you find that you just can't hold the enemy ACU back, you may find you have to abandon your base. The best thing to do in this case is to try and retreat to the enemy's base. It will likely be ungaurded or lightly gaurded, and taking out any pd and engineers is usually easy enough. You can often then capture the remaining structures and begin to fortify your new base against his inevitable ACU attack.
- If you are rushing massed tanks early on, not only do you not need to worry about a com rush most of the time, but if you find he is rushing you, it's usually a trivial matter to overwhelm the early ACU tech and get an early commander kill.
Here is an excellent guide to counter ACU Rush :