If you were in one of a handful of places in 1995 in the United States, you knew that a revolution was starting. It's been going on quietly ever since, even though most people are still blissfully ignorant of it. This game, Settlers of Catan, was the opening shot.
Before 1995, non-digital games in the US were mostly children's games. If a game said it was a "family" game, it meant that it was a children's game that the parents would grudgingly play to keep the kids happy even though it was about as exciting as watching paint dry. The problem of how to make a game that could actually appeal to all ages, for real, had not yet been definitively solved.
This game itself is fairly simple. The board consists of some hex-shaped tiles that each feature one of five commodities (wood, ore, grain, clay and sheep). Each space has a number on it from 2 to 12. On your turn, you roll two dice, and whatever board spaces match the number rolled will produce their resource type for any players who have adjacent settlements. Next, you can trade with any other players or with the bank (although the bank gives lousy exchange rates, so most of the time you trade with others). Lastly, you can spend your commodities to build additional roads, settlements and "progress" cards (you might call these "Chance" cards in another board game, except they're all useful).
The object of the game is to reach 10 victory points. You get points for building settlements; some progress cards give you a point; and there are also a couple of bonuses that encourage players to either build lots of roads or buy lots of cards. There is more to it -- I didn't get into the rules for stealing, or upgrading settlements to cities, or taking advantage of ports for better exchange rates -- but those are secondary. Primarily, the game consists of a virtuous cycle of production and building, enhanced by player trading.
Settlers uses a number of design techniques to appeal to a wide age range. The board is colorful, and there are a lot of toy bits to play with: cards, wooden roads and houses. There is enough randomness to give weak players a chance to catch up. There is virtually no downtime when you're waiting for other people to take a turn, because even on other people's turns you can still produce and trade. An entire game is over in about 90 minutes, just around the upper limit of a child's attention span. All of these things make the game palatable to kids.
And yet, the randomness can be understood and planned for, allowing a decent amount of strategy. The game's trading aspect is social and engaging. There are many paths to victory (expansion, upgrades, cards and roads can all give you victory points), so a good player uses different strategies based on the board position and market conditions. The game also has a random setup, leading to vastly different initial conditions and giving it high replay value. This all serves to give a satisfying experience to adults.
This is not the only good game to come out of Germany. It wasn't even the first good game from Germany. But it came out at a time when the market was right. Dungeons & Dragons and Magic: the Gathering had established the hobby game market here in the US, and it was shortly thereafter that Settlers of Catan came along and made people re-examine boardgames.
If you've played any other Eurogames, you've probably already played Settlers of Catan, and if you haven't then you probably will before too long. But if your idea of "boardgames" is Candyland, Monopoly and The Game of Life, I'm here to tell you that boardgames can do better. We don't have to put up with "roll a die and advance around a track" as the only way to pass a rainy afternoon. Are you with me? Then join the boardgame revolution, and play this thing!
Ed.: Another point worthy of note: Settlers is, internationally, the single best-selling boardgame in the last ten years, with more than 13m copies sold worldwide. This certainly raises the question as to whether "videogames" are the revolutionary advance some think, or whether interest in games of all sorts have co-evolved in the last couple of decades.