Making voice a rule of the game
In Through the Prism, voice chat is not a tool sitting next to the game. It obeys walls, glass and distance, and the puzzles put that to use.
In most co-op games, voice runs alongside the game. You start a call in another app, you talk without limits, and the game knows nothing about it.
In Through the Prism, I wanted the opposite: voice lives inside the game, and follows its rules.
A voice that exists in space
Voice chat is built in, and it works by proximity. Your partner's voice leaves their character and reaches you as it would in a real room.
Three things follow:
- Distance matters. The further apart you are, the less you hear each other.
- A closed pane of glass cuts the sound. You can see each other without being able to talk.
- A grille lets it through. You cannot walk past it, but you hear each other perfectly.
Seeing each other and hearing each other become two separate things. Everything else starts there.
Why it interests me
Because it adds a dimension to the puzzles. Once voice obeys rules, you can play with those rules like any other mechanism.
Communication can be cut for the length of a room. It can be made one-way: one hears, the other does not. It can be reversed halfway through, so that the one who was guiding suddenly has to be guided.
Each time, the pair loses one way of understanding each other and has to invent another. That is the moment I am after, when two people agree on a code they have just improvised.
When you can no longer talk
The game gives you a few simple gestures: pointing, raising a hand, nodding or shaking your head. They have no imposed meaning. It is up to the players to decide what they stand for.
One of the tutorial's trials rests on this. The two players each end up in a glass booth. One sees a piece of information, the other has the controls, and voice no longer gets through. You have to manage with your hands.
What it takes to get right
The risk is that silence looks like a fault. If voice cuts out suddenly for no visible reason, your first thought is that the microphone has died.
So the cut has to explain itself. You move apart, a door closes, the sound fades little by little: the room shows what is happening, with no message on screen. That is also why grilles, glass and openings have to read at a glance, even in the grey blocked-out version.
Finally, the tutorial checks something very down to earth: that both microphones work. Its first trial cannot be completed unless each player has spoken and heard the other.
No language barrier
No puzzle asks you to understand a word written or spoken by the game. What you need to know comes through symbols, shapes and gestures. Between the two of you, speak whatever language you like.
The next note will be about how I build levels, in grey blocks first.