The Intentionality Problem

Back in 2011, I became obsessed with the video game Achron, which was then unreleased. It billed itself as the "World's First Meta-Time Strategy Game." What made Achron special was its time-travel mechanic. It is an RTS game where you can freely jump around the timeline of your match, and even send units back in time. It captures the feeling of time travel in a way I have not seen in any other game.

For several years, I tried to recreate the feeling of Achron in board game form. The challenge was that board games can't handle the same level of upkeep as video games. But even as I found upkeep mitigations, I ran into a bigger problem: changing the past made actions nonsensical. Time travel breaks the illusion that in-game characters act with intent. This is the intentionality problem.

Imagine a time-travel game with a cast of time agents who move around a board and take actions. Agent Ben and Agent Fred meet in the park to hand off the secret briefcase. Agent Sandy doesn't like this, so she goes back two rounds and murders Agent Ben. But the player's decision to move Agent Fred to the park hasn't changed, so he still goes there in the future. Why does he do this? In a time-travel story, you would expect his decision to change.

The more precise your control, the worse the intentionality problem becomes. Achron worked because it was an RTS, with broad orders like "go here" or "attack this." Imagine a time travel FPS game instead. As soon as somebody starts changing the past, all future actions stop making sense. Characters shoot and hide from phantoms that no longer exist.

The solutions to the intentionality problem are abstraction and vague controls. The higher the game's level of abstraction, the harder it is to break the illusion of intent. If Ben and Fred don't need to be in the same place to exchange the briefcase, then you don't see Fred go to the park. If you don't control every shot a character makes, they can stop shooting if there are no enemies nearby.

The intentionality problem extends beyond time-travel games. I was working on an autobattler where two spaceships flew around fighting each other. The problem was, they moved in two dimensions. If ships moved randomly, they would seem to lack intent. In contrast, consider Magical Athlete's characters, who move randomly around a one-dimensional track. Their actions feel intentional because they always move toward their goal.

I have since encountered several other time travel prototypes. One thing that has struck me is that the more abstract the gameplay, the better the time travel theme lands. The best example I have seen is time travel trick-takers. In trick-takers, you might play a card for any number of reasons. When you go back in time and change the card you played in a trick, the other cards still look plausible. After all, people play high or low cards for all sorts of reasons in a trick-taker. The more abstract the game's theme, the less likely time travel is to lead to implausible actions.