Economic Game Theory vs CGT

When I started grad school in computer science, I quickly learned it was dangerous to admit that to people. "Oh, that's great! You can help me fix my computer!" Though I'm no Linux guru, it quickly became my safe haven: "Which OS are you using? Oh, I haven't run Windows in years... I don't know anything about that." At least that wasn't a lie; I just have no experience cleaning up viruses, etc. Still, I learned it was often easier to tell people I was studying math instead and save the whole explanation. Again, this wasn't too far from the truth. Theoretical Computer Science doesn't look much like computer science to most people.

Nowadays I'm faced with an alternate dilemma related to explaining my field. Talking with other computer scientists, I will often simplify things by saying I am studying "game theory". Sometimes there are no follow-up questions, but other times people will assume you mean economic game theory or derivations thereof. I still haven't mastered handling this situation, but here's how it seems to go.

Me: "Oh, I'm more focused in combinatorial game theory, which isn't quite the same."

Them: "Combinatorial?"

Me: "Yeah, like board games."

Them: "What is there to study there?"

Me (getting all excited): "Well, we try to say things about who can win a game."

Them: "So you could figure out who's going to win a game of Monopoly?"

Me (somewhat less excited): "Well, we try to work with simpler games, like Hex or Chess."

Them: "Chess is simpler than Monopoly?"

Me: "Well, Chess doesn't have any randomness in it-..."

Them: "I think Monopoly is much easier to play than Chess."

Me: "..."

I would much rather replace this with the following conversation:

Them: "Combinatorial?"

Me: "It's similar to the economic side. ."

Them: "Oh. How do you do that?"

Me: "We investigate these things by looking at simple board games. Sometimes what looks simple can wind up being very complex."

Them: "Wow, board games can do that? That's pretty cool!"

Me (beaming): "Yeah, totally!"

I know some of these similarities and differences, but how can I phrase them well? More importantly, how can I state this in a clean way that will not legitimately spark a "whatever!" from someone with a knowledge of economic game theory? A dangerous task indeed!