Calin said:
My goal is to build a RTS with an AI that can read your mind while you are playing against him.

Valve is working on human brain → computer interface, so wait for that to read the players mind :D

But i see what you want is to predict player actions in RTS?
It's ofc. easy math to predict linear movement. Constant speed and no turns. This can be used to hit a moving target with a projectile, where the projectile also has some limited speed and would miss the target if aiming at it directly.
But i guess you talk about real problems, like predicting the players strategies.
I guess the easiest, and maybe the only way to do this is to learn from previous games against that player, or from his actions in the current match so far.
So it's a question about machine learning? Just asking out of curiosity - i surely can't help.
One idea i had is cheating: You react to the players commands, although no NPC unit is nearby to see them. But that's lame i guess.

Only RTS i've ever played was Z on Dos, which was long before.

But i would try this strategy:
Reduce and discretize the game state. E.g. using clustering algorithms to approximate multiple units to a single point. Same for resources and buildings.
Same for the map. Scale it down as much as possible, but not too much so obstacles like mountains or rivers are still preserved.
This won't be perfect, but can be helped with jitter and randomness over time, so abstractions going too far may be seen in a future update.

Due to the simplification, AI can test out more options and think further ahead.
This planning could happen in a round based manner, so time is also discretized.
Then something similar to a chess AI should be applicable to build up a coarse strategy. (usually the videos of this guy are good: https://www.youtube.com/watch?v=U4ogK0MIzqk)
Only

grrr… NEVER EVER post a link into a topic while still typing. Paste them in only after you are done. Then, with some luck, it might even work. >:(

hmm… try to remember what i've wrote below the link…

Only a short duration of future time needs detailed AI, which then can be reduced to local decisions. The simplified coarse system handles global scale and overall tactics.
I would eventually implement the coarse system so it starts from scratch at each update. So it may come up with different solutions each time.
To counteract this, cache a set of promising options, and reconsider them in the next update.
This way the behavior should be more natural, meaningful and predictable.

However, i think you should make a post specifically asking about RTS AI. Some people here should know, but may shy away from topics about AGI, Terminators, animals and evolution, etc.