by BoltKey

Part 1 – Finding the Right Pace & Depth
Those who follow CGE for a while know that a lot of design happens in close cooperation between the designer and CGE after the game is accepted by the company. I was in a bit of a special spot in this project: I have worked as a full-time employee at CGE, and I have worked on Drillers since late 2023.

The process of CGE deciding to publish the game was quite gradual. I was bringing various prototypes to CGE events, some people that liked the game pitched in with their skills to make the next prototype just a little bit better, and this eventually evolved into the crunch of a real project with real deadlines and stakes. Říman, a CGE in-house 3D artist, was a great partner in the initial phase and contributed many ideas that made it to the final game. We spent many evenings brainstorming and discussing the game, and that’s the reason he is titled co-designer on this project.

There was not a singular moment, contract, email or meeting where we decided “let’s do this”. It was almost like a natural progression.

Development and design of the game were a lot of fun and great adventure, as with any game design endeavor I get involved in. I am writing this diary from my perspective (Adam Španěl) as the lead designer and author of the initial concept, but I’ll occasionally use “we”. That means “the development team”, which mostly consists of me, Říman, Tomáš, Elwen and Mín.

The Story of Drillers
Back in 2005–2010, I spent a lot of time playing flash games. It was a golden era of browser gaming. That’s when I discovered Motherload, and I absolutely loved it. The sense of wonder every time you discover a new type of mineral. The satisfaction of selling your haul, finally refilling your fuel at the last second and upgrading your machine. The courage it took to just go deeper, and keep discovering more.

The series that culminated in Super Motherload in 2013 helped define a genre of "mining games" like Dome Keeper, SteamWorld Dig, and many others. They all share the core loop: dig, gather resources, sell, upgrade, repeat.

No board game I have played quite captured the feeling I got from the video games: you know you should probably head back up as your fuel is running low, but there is that really valuable gem just within reach that would be just enough to buy that upgrade you really need. And the next time you get there might be too late. On top of that, your curiosity of what is hiding in the depths is sometimes stronger than your rational decision to just play it safe and return to camp.

Designing for Myself
I know I should probably focus more on who the target audience is when designing a game. However, I am one of those designers who make games primarily for themselves. The games I want to play, and the games I feel are missing on the market. And if other people end up enjoying them too, that's a great bonus. I knew an exact feeling I wanted the game to create, and the only way to play it was to make it myself.

So, I got to work. The very first iteration contained just the core elements: cards that generated moves and drills for fuel, tiles that created cubes that you could collect in your cargo, and when you reached the surface again, you could buy better cards. I am really glad that these core mechanics "survived" in pretty much unchanged form from the first iteration to release.

Of course some of the mechanics evolved: how the shaft tiles worked exactly, and how the card offer worked, how the card management worked, and gradually mechanics like drones, repair, unique effects, floor cards or permanent cards grew around the game, but the core loop was tight and solid.

Abstracting the Mine
One core mechanic of the mining video games is that as you play you’re constantly reshaping the world as you play. You are creating a maze that you have to later navigate, so it has this kind of "build your own puzzle" element to it, and if you are not careful, you might get lost and perish.

At one point I considered playing around with this idea in Drillers. It turned out to be just too bloated in combination with other mechanics, and it added too much unnecessary complexity that was not so fun. So I decided not to explore this direction any further.


Drillers – Mainboard progress

Game Duration
Drillers is a game with variable and player-driven game length. This creates a sense of urgency and a bit of race. This however poses several design challenges.

Balancing the Game
Drillers is all about optimizing your turns and pushing every card to its limit. There is a big difference between what a beginner can do in a turn, and an advanced player. Since the game is timed by what players have accomplished in the game (how much they’ve mined), this creates huge discrepancy between length of different games. While advanced players usually hit the "sweet spot" of 10–12 turns, beginners' games often stretched to 17 or 18 turns. Combined with the natural learning curve of new players, this initially resulted in pacing friction that lacked momentum.

During development, we noticed that many players played it safe and stayed near the surface, working with the minerals that they could reach easily. While that approach worked, it often led to slower and less engaging moments.

We wanted to bring forward the feeling that we love about Drillers. The need to go a little bit deeper, take a risk and get something more valuable. So we started to shape the game to naturally encourage players to dive deeper:

The Market: Encouraging Diving Deeper
Initially, the prices for selling minerals were flat, but we decided we need to make them variable somehow, to make the new shiny minerals more attractive. We considered a shared market, but that was too complicated. Instead, we created the system where the more you sell of the same mineral, the less valuable it becomes. Eventually, we made the silver and gold prices drop to zero credits if they are oversold. It’s basically a way of pushing the players towards diving deeper for more profitable minerals.

The Floor Cards: What Lies Beneath
There was the idea of floor cards adding special rules floating around, but I was scared of it: I didn’t want to add too much rules overhead. But I think they turned out great. The main principle is that the floor cards only trigger when you actively interact with the floor, rather than just passing through. But the main reason was, again, to motivate new players to dig deeper. The curiosity of what is on the next floor really helped this.

It was a challenge to hit that sweet spot with the floor cards so they are significant enough so you want to care about them, but not game-changing in a way that gives unfair advantage to certain playstyles.

Let’s look at the Hot Tub. The first version gave a discount of 1 drill but also 1 damage. This was just bad most of the game, and usually you wanted to avoid it. The intention was to make that floor a bit more dynamic, with easier access to tiles, but the drawback was too much, so the opposite happened, with many players skipping that floor entirely.

In another version we added 1 extra fuel for each tile on top of the damage. This solved the initial problem of skipping the floor, but created a new one: players could suddenly make very unpredictable moves, grabbing 3 or 4 tiles at once and sometimes ending the game prematurely. To restrict it, we limited the effect to once per turn.. But this was still a bit too weak.

In the final version we gave it a major buff, where for the first tile, you get a discount along with the damage to your hand. Now that’s definitely beneficial, but still can bite you if you are not careful.

Another interesting example that highlights the back-and-forth with the illustrations is Lobby.

The original idea was simple: a safe space where you can prepare for your next big turn. At first, it only had the ability of keeping 3 cards for free. That worked quite well, but in practice, the timing often felt off. When the card was revealed, you usually didn’t get to take full advantage of it.

We brainstormed the theme a bit: first, it was just a “safe ledge”, which felt a bit bland. From there, the idea evolved into something more playful–a rest spot for a picnic table next to a vending machine.

When we were thinking about how the floor should work, we leaned into the theme of the vending machine, adding abilities involving money and getting snacks. Adding these effects ate up the space for illustration, so we dropped the picnic table, which evolved into the garden chair.

This quite wild iteration led to a really sweet floor card. It is a perfect example of the “game design informs art, art informs game design” principle that CGE prides itself in following.


Drillers – Lobby Event card progression

Game End Trigger: Making Progress Visible
Finding the right way to end the game took several iterations.

Initially, the end of the game was connected to the total number of minerals sold by all players. That worked reasonably well, but it was a real pain to track during play.

Then we moved on to a system where all the ground tiles had a number of dots, and if you collected 12 dots, you triggered the end of the game. The same issue, you had to keep recounting dots of other players to see if they were close to ending the game.

Then Říman had the great idea of connecting it to the physical size of the tile, making deeper tiles bigger, and slotting them above the player board. It was intuitive and satisfying, but this led to another problem: when players collected too many minerals and kept building their deck instead of getting the fat points on the lower floor tiles, it made the games exceedingly dragged out.

So finally we connected the dots, and made the end trigger by combination of tiles and minerals filling the track from each side. With that, we have a system that is quite intuitive, takes into account both minerals and ground tiles, but more importantly, you see at a glance how far along everybody is.

I am really glad how that one turned out.


Drillers – Progress of the player board

Ending Turns
Another mechanic we iterated quite a bit was the final turns after the game end trigger.

The first option, that is quite common, is giving every player the same number of turns. I usually don’t like use of this mechanic in games for two reasons. First, you must somehow mark or remember who was the starting player. And second, in my opinion, it adds more asymmetry to the player order than with variable number of turns: the last player approaches the end of the game differently than the first–they know exactly how many turns they have left, which can shape their entire strategy.

Instead I prefer giving players later in turn order extra resources to compensate for potentially less turns than others. Some players reported that having less turns than their opponents felt unfair. We tried quite a few solutions until we found something that felt right. First, we simply gave an extra turn to the player who triggered the game end. This, however, led to the extra turn feeling a bit useless and uneventful, and in some ways boring: the final turn should feel like an all-out finish, but the player triggering the end of the game expended most of their resources to trigger the game end, and didn’t have much of anything left for the extra turn. But we still wanted to give that all-out final turn to the opponents.

So, finally, we settled on the big 18-VP bonus for the closing player, that should compensate for the opponent’s extra turn (along with that extra card we gave just to make the final turn feel even bigger) The solution finally felt quite good for all parties involved.


Thank you for reading our Part 1 and coming under the surface with us.
Next time, we’ll dig into the core mechanics of Drillers–deck-building, decisions and how we shaped the way the game actually plays. If you want to get a head start, you can dive into how the game works by reading the rulebook: Drillers Rulebook.

If you want to be notified when the Part 2 drops next week, subscribe to Drillers here on BGG.
Looking forward to reading what you think so far.