When I first got Munchkin, I was excited to dip my toes into tabletop RPGs. I'd played computerized RPGs over the years, but physical D&D seemed too much to start playing with my family and friends. As you might expect, our first game was disappointing.
Munchkin, to borrow a video-game phrase, is a card game with RPG elements. The goal of the game, isn't to get through the dungeon, but to level up to 10 before anyone else does. Role-playing is a means to that end and no story could hold it together. At any point characters might change race or class, if they have the right cards and see a way to gain an advantage. That's hard to explain in game fiction, so this game just doesn't bother.
We finished that first game and I figured I didn't enjoy it because I had misunderstood the concept of the game. (This was many years ago when people would buy games based on the box art. I certainly didn't read internet reviews at that time.) We didn't play again for a while and the box ended up on a rarely visited closet shelf. Recently we moved and rediscovered Munchkin.
With clear eyes about what we were getting into, we decided to play again. It ... didn't go well. It was kinda fun for the first half-hour, but it just took so long for someone to win we were glad it was over.
Maybe you've played Fluxx? It's a game where the rules are printed on the cards themselves, so players can constantly change the objectives. It means a player can be close to winning when, out of the blue, someone else moves the goalposts wiping out the leader's advantage. Alternatively, the new rules might award the win to someone who wasn't close a moment before. On occasion players get just the right set of cards to win in a very clever way. It good for 20 minutes or so to kick off a game night.
But every now and then a game drags on as people can't seem to have the right combination of cards. Between a bad run of cards and aggressive blocking of other players, nothing goes as planned. The fun starts to drain away. Instead of playing something more engaging, everyone keeps working on what was supposed to be filler. The smart thing to do is declare a draw and put the cards away.
Munchkin is like that except there's never a quick and clever game. You always start with ill-equipped level 1 characters who regularly find themselves running away from much higher-level monsters. As characters gain levels and equipment, they have an easier time, but the incentive to cooperate dissipates too. Finally someone gets close to winning and everyone else tries to stop that from happening.
Reading that paragraph again, it strikes me that this could be a very enjoyable trajectory. It's a three-act structure upon which an excellent story could be told. But Munchkin isn't interested in story telling. It doesn't want my human warrior to betray your halfling thief. It wants players to "stab your buddy". It's less a game and more a machine for pranking each other.
For people who jell with that sort of game, there's nothing else quite like it. Which is why there are endless themed expansions, I suppose. (Fluxx too has many themed expansions for the same reason.) It's probably especially suited for a group of friends who want an excuse to spend time together and laugh at (fake) indignities they cause each other to suffer. I can respect that.
My copy seems destined gather dust on the shelf once again. Even if the concept of the game interested me, I don't think it's particularly well implemented. It's surprisingly fiddly and shockingly random. So much depends on getting a monster card you can defeat (ideally without help). So much depends on understanding arbitrary-seeming rules such as Big vs. Small items. There's a rule for selling items to gain a level that seems pretty important which we missed altogether because the rule is buried in the Items section rather than having it's own section under Treasures. But maybe this is in keeping with the RPG munchkin theme?