Players could call the characters in our story using a landline phone. This phone also served as a confirmation system—after players solved enough clues, Jive and Sunset would call them with encouragement. My goal in making this system was to make the phone feel as realistic as possible, while also being easy to repair if something broke. So, rather than remake the circuitry of a phone, I used an Analog Telephone Adapter to convert real landline phones into voice-over-IP devices. I then set up a SIP server on our computer which intercepted all phone calls and routed them to Unity, which played different messages back based on the number dialed and phase of the game.
I initially wanted to use a non-speaker phone so only one player could listen and would have to communicate the information to the others. After prototyping this, I realized it slowed down gameplay too much, especially since multiple players wanted the chance to hear the calls. Furthermore, if the listening player missed any information or couldn’t understand something, another player would end up redoing the call. I tried fixing this with a transcript system, built using subtitle files accompanying each call, but ended up realizing the best solution for us was to put in a speaker phone.