If you want to stop a player from obliterating an AI's base, heres some suggestions:
1. Increase attack based on how many units and guardposts the player has (Sierra did this already, the more units a player has, the more units the AI has) Since the AI already has the base, all self destructing units would do is give the AI an even stronger defense.
2. "Reinforcements"
I'll elaborate. Whenever the player gets simply too powerful, the AI gets a small to large reinforcement army from the parent colony (if this isn't it). This army is based on how many units the player has multiplied by say .2 units. This will beat the player down a good deal. Be careful what units you use in this situation, you don't want to make it impossible for them to live!
3. "Stored Reinforcements"
I got this from the Plymouth raid on Eden's colony.
Simply use CreateGroup and spawn a few tigers if the AI's colony is in trouble. Have a few garages lying around for this. It looks perfectly fine, its like the AI simply stored the army. The main purpose of this would be to beat back the player. You could do it so the AI builds the garages and moves units into them.
4. Limited Entrences: Entrances to the AI's base does not exceede more then 2-3 (the more entrances, the harder it is to effectively defend) Entrances are narrow, and longish (boxes in player's units, forcing them to use a MUCH larger army to attack to succeede, especially if all the AI's units bunch up in the entrance.) This can slow a player down a LOT.
5. Well placed guardposts throughout the AI base as well as at the entrances can really be a pain to take out.
6. Walls are great vs microwave rushes! Stick a few EMP along it, and whatch them drop like flies under some railgun/RPG fire!
7. Beware the well timed Vortex in the middle of your attack army! (no timer necessary, once a player's army nears a certain spot, spawn a vortex!) Can also be used to distract a player during an attack.
8. Despite what people say, well placed Acids can really do a lot of damage, particularly in narrow entrances.
As for attacks:
1. AI attacks with a force slightly larger then what the player currently has
(multiply by .2 = how many more units AI has maybe?)
2. AI attacks get increasingly stronger, moving up from Lynx to Panthers to Tiger attacks. Don't let the AI attack with a few lynx just because the player has no defense. This is why that self-destruct trick works on the Sierra maps!
3. If mixed groups of Lynx and anything slower (IE Tigers) have rally points close to the Player's base. You don't want the attacking one group by one group. This significantly weakens the total attack.
A way to disguise this is to have the Tigers move out first, when they are half way, send lynx to the rally point. The army is larger then the player originally thought this way, and they won't attack in small, easily managed groups.
4. Night attacks! ( you already do this)
And thats all I can think of at the moment.
