Win as minor

I'm just going to start trading minor races colony ships so they have many planets themselves lol

This is what I always do, I give them several planets and have them go fight my wars for me, traded for tech , or use them as a buffer between me and someone I don't want to be fighting yet. My very own neutral zone! In fact that'd make for a great minor race, called the neutral zone, independent planets that don't side with anyone.

Interesting ideas. I'll certainly be giving them a go

It has been stated that you cannot play as a minor. However, it is possible someone can mod this to be so. In the base game you cannot play as a minor nor can a minor win the game.

Here is the thing, once you start conquering and colonizing worlds, you are essentially a major. The only paths to victory for a true minor would be tech or ascension, both of which would consist of optimizing one planet and hitting the turn button a lot. Go ahead and mod it in if you want, but it doesn't sound very fun to me.

If you could jump out to a large enough lead over the other major races, you could start producing colony ships for 1 or more of the minor races or give them planets and let them be a huge force in the game even though they wouldn't colonize.

I would hope they would allow them to invade planets although high in their tech tree with low priority unless other factors are met to give them a chance at conquest victory should certain factors play out. 

One factor would be a galaxy with just enough systems created for there to be a system for every race major and minor making it that many races may only have 1 maybe 2 worlds for most of the early part of the game, give them a fighting chance if they stick around long enough....

Other options would be as mentioned in other posts make there a reason to keep them alive and not conquer them, say they would give you a good trade resource or production/research boost if you're allied with them versus just killing them off...

I don't believe minor races are coded to expand in any manor, including invading. I would imagine however that the AI is very similar to major races but by removing its ability to expand. Either by just preventing it from making the proper ships, or completely removing its logic to use them. Honestly I'm interested in seeing which it is. I personally just used the minors as easy pickings most the time, but I fully intend to toy with them now that I have been given a few new ideas about them. Buffer zone.. That might be a tuff one to pull off without actually using your own ships against another major race late game. Giving them colony ships or added planets. Cant say that ever crossed my mind but now it's personal goals The fun things a community can think of are boundless.