Explain Eclipse Phase to an outsider

It might be easier to think of yourself as playing a human mind uploaded to any number of bodies. Your character may be comfortable with that... or severely *uncomfortable* with that.

I suppose the thing to remember here is that one of the key philosophical questions of tranhumanism in the first place is : "What defines you as a human?"

Is it the body? Genetics? Which part, and what about natural mutations - does being an albino then make you not human? Are you still human if this wasn't your first and original body? Perhaps being human is cultural? Do you have to have been born on earth to be 'human'? What about born in an earth settlement? How about on a ship? How about in a test tube? Is being human based in the mind? What if you have a mind that is in all meaningful ways identical to a mainstream human, but it was formed in an uplifted octopus, or on a server? Where's the line?

There really isn't any good solid answer to your question - you've hit one of the key questions this setting is meant to provoke. This is the kind of question that philosophy majors spend their lives exploring.

Answering that question for your character or yourself is what playing the game *is*.

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To step away from the philosophical answer, to something probably more coherently useful for you:

Eclipse Phase is centered on three principles: transhumanism, space-horror, conspiracy

Transhumanism you've already discovered, and as I described above it's a bit of an intellectual can of worms. Space horror and conspiracy are more obvious in the setting: On the one hand there are very large and very potent threats to the existence of humanity, and they're right on our doorstep. They already claimed Earth, they might come back tomorrow for the rest of us. On the other hand, humanity remains one of it's own greatest enemies, and the all-mighty-dollar is a potent force of greed and corruption.

It's all based in space, mostly within our solar system, with as firm a grounding in real world physics as you can get and still be interesting science fiction. Humanity has traveled and changed over the years to take up many forms and new approaches to life, but we still retain all out 'bad habits'. We still have greed, pride, and all sorts of the bad in with the good.

So many of the plots you would see in an Eclipse Phase game are familiar and classic, stories of revenge, betrayal, saving the world, or just your small section of it, or just yourself by any means available, even if that means hopping to another body before your current one bleeds out.