Are you excited to try out SETI: The Search for Extraterrestrial Intelligence, but don’t have a regular gaming group to play with? The good news is that SETI has a robust solo mode that’s easy to manage, doesn’t have a ton of upkeep, and plays very similarly to the regular multiplayer experience. Whether you enjoy solo play or perhaps want to get in a few extra reps ahead of your next group gaming session, it’s worth taking a look at what SETI’s solo mode has to offer. In this article, you’ll learn about how the solo mode works and hear from designer Tomáš Holek about the creative process that went into crafting it.

For anyone unfamiliar, SETI is a heavy engine building and resource management euro for 1-4 players that pays homage to space and planetary exploration, astronomy, and the ongoing search for signs of life in the vastness of space.

Players each control a space exploration agency, relying on real-world technology and techniques to unravel some of humanity’s greatest mysteries. Through careful use of limited resources, you will launch probes, explore planets, listen to the stars, and advance the science of exobiology. The ultimate goal is to discover and study alien life, while being the agency to make the greatest contributions towards this achievement along the way.

How does solo mode work?

In a solo game, you’ll face off against a game-controlled rival research institution. Solo play basically acts like a two player game with one significant change: it uses objective tiles that are not used in multiplayer games. These special tiles give you quests to strive for to hinder your automa opponent’s progress.

Solo mode has five different difficulty settings to challenge yourself with, and the number and level of objective tiles used is what determines the difficulty of the game.

As you play through a standard solo game, you’ll also work to complete objective tiles to whittle away at its end-game scoring engine. The rival automa’s actions are determined turn-to-turn using a special deck of cards. Each card has multiple possible actions, and the rival will always try to take the top action first (if possible), or it will work its way down the card until a possible action is taken. The rival institute’s actions replicate the things a real opponent would do in a multiplayer game, in essence.

Balancing challenge with ease of use

“I wanted a solo mode that would be truly challenging, which means a lot of difficulty levels, with the hardest one being really tough to beat,” says Tomáš. “Before I started designing the solo mode for SETI, I set a few clear goals. The solo mode had to be against an automa, not based on points. The automa's turns had to be quick, and managing the automa had to be simple.”

Surprisingly, the first version of SETI’s solo mode that was tested is almost the same as the final version that appears in the game, he explains. Of course, solo play went through significant further development, balancing, and lots of testing to fine tune it, but it looks and plays very similarly to how it was originally designed.

“For the first few months of solo development, we tested the physical prototype directly at CGE. This meant that a lot of CGE people kept testing the solo mode over and over. I also tested it a lot,” he says. “Once we were confident that it was working well, we made the solo mode available for testing in an internal online testing tool. There, a huge number of reps were tested, and we gathered a massive amount of data. One of our regular testers, Ruda, is a big solo player and managed to test the solo mode for SETI around 50 times in just a few weeks.”

One of the big challenges of designing a good solo variant is making sure it behaves like a real opponent would, while also keeping it fast and easy to operate. “I myself don't really like it when a solo variant has a whole player board, an extra board, and it actually takes longer and more time to manage than a player’s regular turn,” says Tomáš, who prefers a streamlined automa experience with simplified actions that keep the pace of the game moving along. “But at the same time, it still has to be fun to play, and juggling all this together can be challenging sometimes.” With SETI, he adds, it was particularly tricky to design the rival so that it could interact with alien species, since each species behaves differently and enters the game at different stages.

A big fan of solo design

Tomáš enjoys playing solo games quite a bit, he says, and his preferences skew towards pure solo games that are designed for only one player from the get-go. He typically tests out solo modes for every game he acquires as well, since it’s interesting to explore how each designer implements solo play in different ways. Some favorite solo experiences include games by David Thompson (such as Soldiers in Postmen's Uniforms, Lanzerath Ridge, and Pavlov's House), as well as Spirit Island, Cthulhu: Death May Die, Ark Nova, Under Falling Skies, and Thunderbolt Apache Leader’s solo mode.

Another of Tomáš’ recently launched games, Galileo Galilei, also has a strong astronomy theme and a solo mode that was designed just a few months before he began working on SETI’s. “The similarity I see is that in both games, players play against an automa, which I personally prefer,” he says. “However, in Galileo, players compare their strength with Danish astronomer Tycho Brahe, which can sometimes be quite difficult.”

Currently, he’s working on designing a solo mode for another game, Forestry, which is designed by his friend Michal Peichl and will also be released by Pink Troubadour at Essen 2025. Tomáš also has a pure solo game of his own in the works, too.

“I think I primarily learned a lot about game design and how board games are really made, not just the solo mode, but from designing the entire SETI game and the collaboration with CGE, which was very intense,” he says. “The solo mode was more like the cherry on top.”