Note: This is a module review. I have tried not to provide too many spoilers, but inevitably there will be some. Also, this is not a playtest review - it is purely based on my impressions reading it.
The back of The Vault of Larin Karr promises a mini campaign setting. When I flip through it in the shop, I see lots of villages, ruined temples, wizards towers and the like. The writing looks good, the encounters look fun, so I'm sold. When I get it back home, I notice something significant missing. A plot. Sure, there's a few hooks to get players into the valley where the adventure is set, and there's a minor noble who hires the players to evict some goblinoids from one of his properties, but from there on the players just wander around slowly getting closer to the eponymous vault.
This is were the adventure has its greatest strength. It seems that every NPC has some secret involvement with another NPC (and there're about 50 NPCs), and every location is connected by a secret tunnel to some other location. It reminds me of the Ultima computer games, or possibly Scooby Doo. Everywhere you go, you find a new adventure. Fortunately it's all done very smoothly and believably. For example, a passage from the extensive underground area comes up in someone's basement. Said someone knows perfectly well what lies beyond the locked door and has prepared accordingly for uninvited guests from below, so players who stumble through will have some quick explaining to do. The setting is also dynamic, in that things change while the players are there. Another example: Peasant A's farm has been taken over by monster B, so A goes to the local witch C. C cannot handle B, but knows D and E can, but they live on the other side of the valley. C asks players to take a message to D and E (she doesn't think that the players will take on the B for free, but knows they will probably want to visit D and E anyway). The players can make a powerful ally by defeating B anyway, but if they don't, D and E defeat B but spend the next few days recovering, during which they can't help the players.
The maps are reasonable, better than Rappan Athuk but not as good as WotC's. The layout is excellent, and I could follow all the various plot threads without confusion. Four for style. The module itself will usable for many, many sessions. It is easy for a DM to plug in extra locations, and just as easy to take out existing locations for use in a separate adventure. Five for substance.
