While Fallout presents itself as a game that can be played many different ways, any vet can tell you that more than half of the stats and abilities you can focus on are next to useless. If you decide to be a sneaky character who lays traps, or, say, a heavy gunner who's skilled at healing, or really anything resembling a balanced character, you will not make it halfway through the game. So there's that.
What makes the game worth playing is the setting and the story. Not the main plot, which any 4th grader could come up with (find the water! now kill the mutants! hey you win!). It's the story behind the world itself that makes the game work. Sometimes somber, occaisionally hilarious, it makes you want to laugh to keep from crying. Everything else is just baggage.