What's that Word

June 3, 2008 12:44 PM

What is the word or Phrase for a situation where competing persons become emroiled in a "sub game "? A different level of competition, so to say. Relates to game theory somehow. It may or may not include the word "pareto". Thanks.
posted by Student of Man to society & culture (8 comments total)

Is the phrase you're thinking of "subgame perfect Nash equilibrium"? The word for what you're describing is just "subgame."
posted by ewiar at 12:55 PM on June 3, 2008

Wikipedia's definition of a subgame is pretty good. A subgame is any section of a larger game that can be sensibly isolated and solved on its own. In other words, strategies within that portion of the game wouldn't depend on any information from the rest of the game.

Subgame perfection is a little different. The Nash equilibrium is a broad enough concept that in many complex games there are tons of Nash equilibria, not all of them logical. You can get nonsensical outcomes based on non-credible threats, that sort of thing. Subgame perfection is a refinement that tosses out all the equilibria that rely on strategies that are not Nash within their subgames.
posted by shadow vector at 1:07 PM on June 3, 2008

It's not game-theoretical lingo, but two related ideas in general gaming include the "side bet" for additional bets by a subset of contestants on the outcome of a contest, and a "side pot" for a subset of contestants exceeding the stakes at which the whole set of contestants can wager.
posted by cortex at 1:14 PM on June 3, 2008

Pareto efficiency?
posted by mattbucher at 1:33 PM on June 3, 2008

Student of Man might also be thinking of repeated or iterated games, where a single "stage game" is repeatedly played. Here, players can have larger-scale strategies about the strategies they will employ in each stage game.
posted by ROU_Xenophobe at 2:11 PM on June 3, 2008

That's correct, it may be a subgame or a super-game that incorporates into the overall strategy of a "game". I remember reading somewhere in wikipedia where this was described with a latin phrase (two words). Thats what I'm really looking for. Before I made this post I searched the subgame page in Wiki and could not find it.

Truthfully, I'm just making a list of latin phrases that have mileage in the English language (Id est, A priori, De rigeur, Mea culpa,Ipso Facto,Ad addendum, Ergo sum, Sin qua non Et al, Etc.(etera) ) for my own expressiveness and intellectual flair. I found them while reading and wrote them down.

This "subgame" concept though, which is flexible and eloquent with all sorts of parallells through the discplines has a snazzy latin phrase that helps you describe the concept withouth having to say "subgame". Especially when talking (thinking) geopolitics, social power imbalances, etc. , whereas "subgame" would seem innaproriate.
posted by Student of Man at 4:18 PM on June 3, 2008

It's a long shot, but I know in my Googling on subgames and Latin I got a lot of hits on "ceteris paribus" which means "all things being equal". My answer relates to the frequency of the hits in Google on game theory pages and the fact that you said it was a two word Latin phrase. But clearly the meaning is extremely tangential to subgames.
posted by forthright at 10:11 PM on June 3, 2008

P.S. - if you're trying to make a list of latin phrases did you visit here?
posted by forthright at 10:13 PM on June 3, 2008