Reactor 21 changed quite a bit as I tested different versions of it. The basic idea was always there—two players trying to keep a failing reactor stable—but it took some back-and-forth to figure out what actually made the game interesting. Early versions had the right intention, but some of the mechanics didn’t create the amount of teamwork or pressure I wanted. The game felt like it needed a bit more structure around how instability spreads, what happens during a meltdown, and how the players recover from setbacks.
Most of the improvements came from simply seeing how people reacted to certain moments in the game. Some rules felt too loose, and others were a little unclear in how they resolved. Adding the Nuclear Waste pile, tightening the meltdown rules, and clarifying how cards move between piles helped everything feel more intentional. The goal was always to keep the experience focused on communication and shared decision-making, and those adjustments moved the game in that direction.
During all of this, ChatGPT was helpful for keeping things organized. Any time I adjusted a rule or tried a different way of handling a reactor event, I used ChatGPT to help rewrite the sections cleanly, make sure the terminology stayed consistent, and compare versions so nothing got lost. It also made it easier to step back and look at each revision as a whole instead of just patching small pieces. The mechanics themselves still came from testing and intuition, but having a tool to structure everything made the development process a lot smoother.
Reactor 21 ended up feeling more balanced and readable because of that steady cycle of testing, revising, and tightening the language around the rules.
The three acts of the game are as follows:
Act 1 – Getting your footing
The game starts off pretty gentle. You’re drawing cards, placing them where they fit, and getting a feel for how the reactors behave. Most cards go somewhere without much trouble, and the token tracks are empty, so nothing feels dangerous yet. This is where you learn the rhythm: keep totals tight, stabilize when you can, don’t waste options.
Act II – Things start heating up
Now the reactors are filling up, and suddenly every card matters. A placement that was easy earlier now feels risky. You’re choosing between Instability and Meltdown more often, and both choices actually hurt. The Nuclear Waste Pile kicks in and you start to feel the deck thinning out. This is where the team talks things through, plans moves, and tries to stay one step ahead of the system.
Act III – Hold it all together
By the end, everything’s tense. One bad draw can end the whole run, and every card feels like it might be the last piece you need—or the thing that breaks the grid. You’re trying to lock down those last stabilizations before either track fills up. When the final reactor hits 21, it feels earned; if the system blows, it’s usually by a hair.
(Final thought created with the assistance of AI, using my input)