The official adaptation of the famous board game Mysterium!

Mysterium is a cooperative deduction game set in the 1920s in which a ghost guides a group of psychics to uncover a murderer, as well as the weapon and location of the murder, using only visual clues. Choose your way to play: take on the role of the ghost who gives others clues, or as one of the psychics trying to decipher the abstract "Vision Cards".

It was the first project developed as a part of cooperation between Playsoft and Asmodee. I was responsible for the entire technical side of the project, from preparing a quote and estimations, to training juniors.

One of the main challenges from the technical side was multiplayer implementation. Publisher insisted on using their in-house solution for backend and multiplayer state control, as it was already used in one of their other games. Unfortunately, the solution has a lot of technical limitations - for starters, it was designed for symmetrical, competetive, turn-based games with only one player interacting with the state of the game at any given time. By comparison, Mysterium is a cooperative, asymmetrical game, and while the manual defines a concept of a "turn", it's also completely real-time, with all players making their decisions ad hoc. Backend also doesn't offer the most basic multiplayer features, like allowing players to change the existing lobby settings or even manually starting the game. We narrowly avoided turning it into a complete hack-job by some ingenious out of a box engineering. Most features players come to expect are simulated seamlessly client-side, outside of the real backend logic.

Another challenging, but also very interesting, feature to design and develop was AI. "Mysterium" gameplay is all about communication via image, and there is no single winning strategy or algorithm that could allow AI to perform well. Perfect AI for a game like this is AI that behaves like human, but how to translate associations - physical, cultural, or abstract - between few hundred cards, each with very detailed art - without outright cheating, as that would hardly make for a compelling gameplay? We came up with completely custom card estimation system, in which every one is described with keywords - which could be objects, colours, themes or even moods - with varying weights from the strongest to the weakest. We also involved volunteers - board game fans - into card estimation process by preparing questionnaires and secondary helper app. As a result we ended up with a huge base of ontology for the entire card pool. Our AI players, both filling in for the ghost or for the mediums, can then traverse this base to make correct - and more importantly human-like - decisions during the game. As strength of relation between each pair of cards isn't simplified to a single variable, both human players and AI can make use of more "meta" strategies, such as using multiple seemingly tangentially related cards that share the same concept in order to accentuate it.

After initial release we were also able to use analytics - analytics used for good not evil, that must be the first one in this industry, huh? - to further fine tune our association base by detecting which cards real human players play together.

Game mechanics are complemented by a single player story mode written by our designer Aleks Druzhinin. It's a classic whodunnit mystery with a paranormal twist, in which you play as a journalist trying to uncover culprits in a series of seemingly unrelated murders in 1920s.

"Mysterium" was a modest success. We followed the base game with expansion sets - "Hidden Signs" and "Secrets & Lies" - based on the board game expansions, as well as some free unlockable content and challenges. We also introduced some new mechanics and features exclusive to the digital game, like Blitz mode and hot-seat mode.

You can buy "Mysterium" on Steam, Android, and iOS.