For between two and five players, the game involves building rail routes across Europe. To build the routes you need cards with appropriately coloured wagons, picked up two at a time as a go in the game, and there are various additional considerations to cover, such as a set of specific routes you need to build if you are to have a chance of winning (allocated by randomly selected cards), and a bonus for the player with the longest single route at the end of the game.
The play is an excellent balance of luck (how you build your route is dependent on which cards you pick up) and strategy/tactics, meaning that a good player will usually win, but a less skilled player can win occasionally, so doesn't feel it's pointless to try. You don't have to be interested in trains, by the way - that part is almost incidental - it's effectively about building a network.
To begin with it seems almost impossible to remember everything you are trying to do, but players soon develop strategies that make for a good chance of winning... if it weren't for your opponents. With two taking part there is relatively limited interaction between the players, though even here one will often block the other - with four or five playing, the whole blocking business becomes a major part of the game. If someone gets in your way, you either go round them (and hopefully block them back), or can use a station to piggyback on their line - but this loses you points and means you can't get the longest route.
A two player game typically takes about half an hour, with time increasingly proportionately with number of players. It's addictive and great fun - highly recommended. You can also get other areas of the world, and expansion packs that add extra rules and complications.
Ticket to Ride: Europe is available from amazon.co.uk and amazon.com.