2 Tone Game: Dualtone Design Notes

 

SPOILER WARNING

This page contains spoilers from the 2-Tone Game. If you haven't already played the game, you might want to do so before continuing reading this page.

Dualtone is a math puzzle that solves to a phone number; a player calling the phone number hears a message. In the original version of the puzzle, the message was just an answer to enter; in the final version of the puzzle, the message told the players to enter "PART B" as an answer; this revealed a little run-around to solve.

Here's the original puzzle; this core part didn't change:

Go to the Golden Gate Ferry Terminal behind the San Francisco Ferry Building. There you will find two pay telephones.

Some telephone keypads send their signal via Dual-tone multi-frequency. Each row of buttons on the keypad has a sound frequency associated with it; so does each column. When the user presses a key, the keypad combines the sound frequency of the row with that of the column to generate a sound wave.

Combining sound waves is hard. What if we just added frequency numbers instead?

Suppose these payphones' telephone numbers had "frequencies"

24 29 7 21 15 21 21 and

24 29 7 21 9 15 7

...then what would these frequencies mean:

21 24 6 9 24 12 14

The first batch of playtesters said that the puzzle seemed kind of skimpy. Why shlep all the way over to the Ferry Building for a little data just to solve a puzzle in 10 minutes? So I tacked on the extra runaround at the end, and people seemed to like that better. Though someone did notice that this felt "tacked on". And people did seem to wander away from the ferry building before solving the puzzle, and weren't pleased to find out that they'd have to go back to finish the puzzle.

To get a phone number that would play a short message to the players, I used Google Voice. It let me choose a phone number from a few choices; I picked one that used many digits that didn't appear in the payphones' numbers.

Back