Clank! Catacombs: Underworld Design Diary 2: Navigating the Underworld

July 14, 2025

In the last Design Diary, I talked at a high level about how the underworld is a fixed destination where you can go. But I didn’t talk about how you can get there (except, obviously, via Kickstarter!). In this article, we’ll address that and more.

Welcome to the Underworld

The Underworld expansion comes with different types of tiles. The largest one – the underworld starting tile – is the one that you place at the start of the game. Oh, and this tile is double-sided so you can choose which side to use for the game, similar to the Catacombs starting tile. (Note: This tile being double-sided wasn’t taken for granted during the development process, but I really wanted it to have two sides, and the team spent the needed extra weeks of playtesting and development necessary to bring it to you!)

The second type of tile in the expansion are the regular underworld tiles, those that are placed adjacent to the starting/central underworld. These tiles aren’t placed until you explore there. But how? How do you get from the regular catacombs to the underworld? There are actually a few different ways to do so, but the most common case is: ladders.

Chutes and Ladders

The expansion comes with six new depths tiles, each of which has either a ladder or an underworld chute that can bring a brave thief to the underworld. At the start of the game, you’ll shuffle only three of these tiles into some of your other depths tiles to form a stack of depths tiles where you’re guaranteed to find three ways down in the top 10 depths tiles. (This works the same way whether you’re playing with Lairs & Lost Chambers or not.) Most of these ways are ladders, but you may also encounter the occasional chute! Ladders allow you to climb back up to the catacombs, but chutes are a one-way ticket down to the underworld — you’ll have to find a different way back up!

Each ladder is labeled with a letter that corresponds to one of the sides of the underworld starting tile. This indicates where you’ll go if you descend the ladder. From a gameplay perspective, this is very important, because I wanted players to have interesting decisions of whether and when to descend.

For example, let’s say you started out the game and acquired some high-skill cards but very few swords. In your mind, you’re going down a strategic path towards Secret Tomes and you’re hoping to get an Imp Assistant (who we introduced last time!) Now, let’s say you’re exploring the depths and you discover the “A” ladder tile. This is not the greatest ladder for you, since the “A” region of the underworld is on the opposite side to the Forbidden Library. You were hoping to find a “C” or “D” ladder. But you simply can’t count on finding the perfect ladder all the time, and remember, only three depths tiles have paths to the underworld.

So, you’ve got a decision to make. Do you descend down to the “A” region and simply get what you can? Do you descend to the “A” region and hope to work your way around the underworld, reaching the Forbidden Library “the hard way”? Do you leave the “A” ladder behind and continue exploring the depths? Have the other players in the game discovered any routes to the underworld? If so, how far away are they? As you can see, there are a lot of factors involved.

The Underworld Toll

Oh, and there’s another important factor that I haven’t even mentioned yet: underworld tolls. You see, while we decided to make the underworld a fantastic place to go to get valuable treasures, we also decided to add some friction to the player experience. Something for you to consider when deciding whether to descend. This friction comes in the form of a literal toll. Whenever you start your turn in the underworld, you must pay 1 undercoin to the bank. And if you don’t have an undercoin on hand, then you must make +2 Clank! at the start of your turn instead. So, what’s an undercoin?

Undercoins are a new form of currency introduced by the Underworld expansion. In addition to paying underworld tolls, they can also be spent as regular gold coins. You can gain undercoins in a variety of ways: from certain rooms, from cards, and from defeating monsters.

So, as you can see, reaching and exploring the underworld isn’t a decision to be taken lightly. You might be factoring in what your goals are in the underworld, but you also should consider how many undercoins you’ve got to spend. Can you sustain your expedition into the underworld without making a ton of noise? If you’ve got a lot of boots, perhaps you’re aiming for a brief in-and-out expedition. If you’ve got a lot of swords, you might have more opportunities to earn undercoins during your expedition. We’ll talk about that in the next design article! For now, though, let’s take a look at some cards that can give you undercoins: