(Spoilers ahead for "Lair of the Lamb" by Arnold K. You should check it out if you haven’t already. It’s free on Goblin Punch and has become one of my favorite adventures.)
In the adventure "Lair of the Lamb," there is a tumbler puzzle. It’s basically a combination lock where players spin disks to display the correct numbers to open a door. Wrong combinations cause wandering encounter checks via loud grinding machinery behind the scenes and a refreshing bath of milky, flesh-sizzling acid.
The only clues to the correct combination come from another room with a fountain where water drips in a pattern (drip, drip-drip, drip, drip-drip). There’s a statue in the fountain room which depicts the same creature as the statue in the tumbler puzzle room—a fish with hands. The statue serves as a hint to search for a numerical combination somewhere here.
This is not an OSR-style challenge, therefore it is not an OSR-style puzzle. There is no challenge for players to assess and execute a plan. There is only hidden information.
This puzzle relies heavily on players making several sequential leaps in logic.
1 The tumblers and door form a combination lock that can be opened.
2 The fish statue in the fountain room is a signal to look for a numerical combination for the tumblers in the puzzle room.
3 The dripping noise in the fountain room is the combination to the tumbler puzzle.
Some of these conclusions might seem obvious when I put them in a list, but they are actually quite difficult to come by naturally in a typical TTRPG session. The referee needs to be on-point with their descriptions and driving home the clues. Players need to remember a lot while also making non-obvious connections. Kind of a lot to ask in “Lair of the Lamb” which is a teaching adventure intended for beginner old-school referees and players.
The good news is that this puzzle is optional. The tumbler puzzle room (and the throne room beyond it) can be removed completely without affecting the adventure at all. But you don’t have to get rid of all of it. With a few small tweaks, we can turn this into a satisfying challenge and enhance the overall puzzle experience for players and referees.
The first step in improving the puzzle is to establish a theme that reinforces the logical connection behind it. Instead of relying on a combination lock with one solution, we can draw inspiration from the existing elements in the adventure. In this case, we have fish statues and water. Moreover, the adventure begins with the party waking up in a dungeon as sacrifices, lacking any inventory (or pockets) to solve their first challenge: finding water. This setting provides an opportunity to incorporate water and dehydration as the central theme for the puzzle.
To integrate the water theme, let's re-imagine the fish with hands in the fountain room. Instead of merely being present, the fish statues can be depicted guzzling water from a stream above. Now let's put that same statue in the puzzle room without the stream of water making sure we describe its mouth turned upright, as if it is expecting something to be placed inside—specifically, water. To further reinforce the connection, murals on the walls can depict peasants in supplication to a fishy god, with streams of water raining down into their unworthy landlubber mouths. This visual representation will emphasize what is absent from the puzzle room: water.
Players still need to drink water from the fountain room, and upon encountering the identical fish statue in the puzzle room, they will have a reason to return for more. The actual challenge lies in how they will transport the water from the fountain to the puzzle room. As written, the adventure provides a few containers for liquids, such as wine bottles and a bowl. Without backpacks or pockets, players need to think about who is carrying what and possibly giving up the chance to defend themselves by carrying water across the den of the lamb. The water and its container serve as a combination “key” for the puzzle room door, but with an emphasis on knowledge acquisition traded for one on planning and execution. Alternatively, players can devise other creative methods to open the door. The fish mouth may accept liquids with a "high" percentage of water, leaving it up to the referee to judge what qualifies as a watery enough liquid—be it sweat, urine, or even spit.
To add an element of risk and consequence, we can even keep the milky acid trap from the puzzle room. If something that is not "watery" enough is placed inside the fish mouth (vinegar, mud, a finger), the statue can react by vomiting up acid and spraying the room. This consequence still serves its original purpose as a deterrent, urging players to think carefully about their actions and the liquid they choose to transport.
With these changes, the players now have a clearer understanding of their multi-step challenge: they need to get water to the fish statue in the puzzle room. However, the solution is not immediately apparent, as they must also consider how to transport the water effectively. This revised puzzle design encourages player engagement and critical thinking while providing a logical progression that enhances immersion within the adventure. It’s an OSR-style puzzle.