Themes in boardgames are a favorite subject of mine. I'm sure I've said before how interested I am in the themes these games of ours have. Some themes instantly attract me to a game, while others are an immediate turn-off. When I'm playing a game, I particularly enjoy historic theming on the cards, or historic notes within the rulebook. You'd think that makes me a theme-gamer. I certainly thought so. But then I thought about the games that were my favorites, and in many cases they are those elegant German-style games that are pretty spartan when it comes to theme compared to recent titles from Fantasy Flight or Days of Wonder. In fact, I don't care for the those other games. In some cases it was because I didn't care for the theme itself (e.g. fantasy battles or dungeon crawl), but in other cases I didn't like how the themes I do like (e.g. gaslight London) overwhelm the game mechanics, taking aware from their elegance.
Enter Greg Pettit, who suggested that there are two distinct types of themes in games. Some provide the evocative experience with art, special rules, a story arc, character roles, and so on. That's what Greg calls "theme as narrative." The other type Greg calls "theme as metaphor," and it usually relates the subject of the game into its mechanics. Some games exhibit both types, others skew strongly toward just one type. I imagine everyone can appreciate those few games that manage to succeed with both of these thematic types, but when it's one more than the other you'll find your gamer preferences shining through. In my case, it's for theme as metaphor, which is why I prefer Vinci to Small World, or Entdecker to Blackbeard.
In this podcast Greg & I talk all about this topic, consider several games under his descriptions of theme, bring in the topic of simulation in wargames (a little), and think about why we prefer certain games and not others based on the way they implement their themes. Over on BGG I'm also posting a poll where listeners can rate a bunch of popular games low/medium/high in theme as metaphor, and theme as narrative.