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Safecracker

A high-stakes safecracking game with a custom alternative controller

Lab
Timeline
  • 2019–2021
Role
  • Interaction Design
  • Software Development
  • CAD & Fabrication
Tools
  • Processing
  • Arduino
  • SolidWorks
Outcomes
A player choosing a heist on the laptop mounted atop the finished safe, one hand on the brass handle

summary

Let’s face it: pressing a button or tilting a joystick won’t ever feel as satisfying as hurling a fireball or gobbling up power pellets. True embodiment calls for alternative controllers that leverage custom-made sensors rather than off-the-shelf inputs.

As part of Georgia Tech’s Interactive Product Design Lab, we built Safecracker: a game where you crack a safe by listening closely with your trusty stethoscope. After debuting as a class project, we polished the gameplay and took first place in the CHI 2020 Student Game Competition out of more than 50 entries in the Innovative Interfaces category.

I am impressed by [Safecracker’s] rich juiciness as an audio-based game with environmental and disturbing sound design

CHI 2020 reviewer
The finished Safecracker cabinet with its stethoscope and brass dial

my role

As the project’s game designer, I translated common safecracking tropes into interactions that could be sensed with electronics. Once mechanics solidified via prototyping and playtesting, I worked with our visual designer to build out the core game loop in Processing.

My favorite part: the entire game is playable without having to look at the screen.

A gloved hand pressing a stethoscope against a copper touch point on the finished safe

how to play

find the sweet spots

Hold the stethoscope to the marked points and listen for the lock’s inner mechanisms.

listen closely

Rotate the dial until a “THUNK” signals the next number in the combination.

crack the code

Solve the three-digit combination and the safe unlocks, revealing treasure on a hidden inner display.

prototyping

Hand-drawn sketches of the safe’s internal electronics: stethoscope touch points, handle and door locks, solenoid feedback, and the dial
Sketched iterations of the safe’s internal electronics — Kelsie Thomas
Copper pads taped to a board with a stethoscope resting on one, wired to a breadboard beside a hand-drawn circuit
Copper tape touch pads to detect the stethoscope
A chipboard mockup of the safe door’s locking mechanism

build & test

The first fully integrated prototype, a simplified boxy safe on legs

prototype build

Our first fully integrated model housed the game in a simplified, boxy safe — just robust enough to test out the interaction model.

A player listening through the stethoscope at a touch point on the boxy prototype while a group watches
Source: Interactive Product Design Lab

playtesting

We showcased the prototype at Georgia Tech’s Industrial Design Student Showcase and captured feedback from 15+ players.

Players found the mechanics engaging and challenging, but we learned the next iteration would need a fabrication overhaul to feel truly immersive.

digital design

System diagram showing the PC, Arduino, sensors, locks, and both displays
A Processing game drives both displays and talks to an Arduino running the sensors and locks.
Players use the safe’s dial and handle to navigate in-game menus.
A playable tutorial teaches the audio cues before the heist starts.
Each difficulty brings its own heist, graphics, and audio distractions.

fabrication

The CNC-routed plywood housing being assembled in the shop
A CNC’d exterior replaced the plywood box.
The frame built to house a screen hidden inside the safe
A screen hidden inside plays the payoff.
A solenoid seated in white 3D-printed mounts
3D-printed mounts for every component
A printed gear and microswitches on one acrylic panel, with a solenoid on a second
Exposed dial and locking hardware
The safe open, showing its internals and the lit inner display
The full assembly of the door hardware and inner screen

outcomes

  • — Won 1st place in the CHI 2020 Student Game Competition, Innovative Interfaces category, from 50+ submissions
  • — Published as an extended abstract in the ACM CHI 2020 proceedings
  • — Playtested with 15+ players at the Georgia Tech Industrial Design Student Showcase
  • — Built at Georgia Tech’s Interactive Product Design Lab with functioning locks and no simulated hardware
  • — Pioneered a gameplay concept supporting audio-based, screen-free play

[Safecracker is] an interesting game design idea that to my knowledge is unique, and is further well designed and well motivated

CHI 2020 reviewer
We also shot a very silly trailer and a complete gameplay demo for our CHI submission, if you’re curious.

Credits

  • Hank Duhaime - Interaction Design & Development
  • Mary Jo Dubina - Mechanical Design & Fabrication
  • Kelsie Thomas - Visual Design & Fabrication

Special thanks