Herd is a single-player puzzle board game, and the latest work of Blaž Urban Gracar, author of beloved puzzle books LOK, Abdec, and Workworkwork. As you can see from the shot above, alongside the book, there are these black and white “pieces”, which will be integral to the whole experience. This is significantly different from the works mentioned above.

But we are going to put aside the medium for now, and focus on the core puzzle mechanics of the game. Essentially, Herd is a “sliding block” puzzle game, which means that when a piece (“block”) move, it would continue moving in the same direction until they hit something. The black pieces are “shepherds”, which the player can control, and the white pieces are singular “sheeps” or connected “herds”, which cannot move on their own.

Obviously, there has to be a mechanic for the shepherds to “lead” the herds, making them move as well. But instead of the standard “Sokoban” (block pushing) movement that most people immediately think of when they see a grid-based puzzle game, Herd introduces an interesting alternative: jumping and stacking. A shepherd can jump over other pieces like in checkers, and if another piece is already at the landing point, a shepherd can be stacked on top of the other piece and slide along with it.

So these are the core mechanics of the game, they feel pretty simple and intuitive overall. However, you might ask, couldn't these mechanics be made into a video game? Of course they could. Even if you account for the mechanic extension in the latter half of the game, you can still implement it if you truly wanted. Herd certainly doesn’t HAVE to be presented in physical form, because it isn’t like those mechanical puzzles which relies on real-world physics to solve. However, I believe the problem isn’t about which medium can “replace” another, but rather what kind of experience the designer wants to convey through this medium.

Blaž's previous work LOK is a good example, as it was already adapted into a video game: LOK Digital. This adaptation inevitably weakened the “rule-discovery” aspect of the original puzzle book, resulting in a completely different feel. Abdec, a work essentially built around rule-discovery, is another example. While Workworkwork contains relatively less rule-discovery elements, providing more feedback than just images would still weaken the unique feeling of “trying to simplify reasoning and visualization through your own means”. If you compare the notes taken by the players while playing these games, you'll find they are all different. I find this to be a charm unique to the print medium.

I could give many more examples if I wanted, but let’s not get too far off track. Ultimately, digital programs are “rigid”, as they could only provide fixed input methods and feedback (output), while human imagination is limitless. But humans also have weaknesses compared to computers in terms of accuracy and reliability, and Herd does indeed explore a mechanic that’s probably better implemented digitally.

All of this is to illustrate that, even if the core puzzle mechanics remain unchanged, the medium of a puzzle game will still affect the "feeling" of solving it. The "feeling" that the designer wanted to present through Herd the most, is the physical, tactile sensation of playing with the pieces with your own hands. The core mechanics of Herd clearly take inspiration not only from “sliding block” puzzle games, but also from the physical interactions in various board games. The mechanics are designed to be simple and intuitive for our human brain to easily process and simulate, and for our human hands to easily control and execute. All to provide that “second-nature”-like puzzle solving sensation.