No evil, there are two types of people who answer that question, you who are constructive, and me who gives a generic question a generic/sarcastic answer just to be an arse

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Answer 1: No, you cannot beat the AI. That's why no one has recorded a victory on the metaverse... ever.

Answer 2: Here's my strategy:
1) Colonize some planets
2) Build up those planets
3) Research stuff
4) Build some ships with the cool stuff you researched
5) Attack the bad guy, or the good guy, whoever really
6) Somewhere you should probably manage your economy
7) Invade some planets
8) Invade some more planets
9) When you fail to invade all the planets, research a tech victory.
10) When the AI crushes you because you forgot to build ships researching your tech victory, scream, rave, blame the game for cheating, smack your monitor, then promptly uninstall.
11) Yell at StarDock for making a bad game, and demand your money back... on the forums
12) Watch us laugh
But seriously...
If you have a specific question, try reading some threads in this Strategy section, especially posts by Mumble, he's good at splainin stuff to noobies. If the answer you're looking for is not there, ask it. But please try not to leave such an open ended question.