Onyx is a computer sex game. Move around the board buying up properties. If you land on a property that is owned by somebody else, you must either pay rent or work off the debt! Players work off debt with all kinds of intimate actions, from mild to kinky. As the game progresses, so does the action! Play with people you are intimate with, or want to be!
You can work off the debt by being assigned fun, sexy erotic actions.
Look out for special squares! If you land on the Torture Chamber, you must draw a "torture card" with an erotic torture on it. At Center Stage, you are put on display; in the Random Encounter square, you will be assigned an erotic action with another player; and on the Fate squares, the luck of the draw dictates your fate.
You control the "spice" of the erotic actions, from harmless fun to wild, anything-goes kink. You choose "roles," which tell the game what kinds of actions you prefer to be involved in. If you don't like being tied up, just tell Onyx that you will not accept the "bondage" role.
Onyx 3.6 and earlier did not work on Macs requiring 64-bit native apps. Onyx 3.7 now works on modern Macs, and is optimized to run natively on Apple Silicon Macs. A version of Onyx that runs natively on Windows ARM devices is also available!
UPDATE: Some Mac users were reporting an error saying “Onyx 3.7.app can’t be opened because Apple cannot check it for malicious software.” I have updated the app to address this issue; it should work properly now.
Onyx runs on Macs (OS X 10.14 or later), Windows (Windows 7 or later), Windows for ARM (Windows 11 or later), and x86 Linux (GTK 2.0+).
Onyx is available for free download. The free version can only be played on the mildest two "spice level" settings. Onyx can be registered by paying the $35 shareware fee. Registration gives you a serial number to unlock the full version, and it also gives you the Card Editor program, which you can use to create your own card decks.
Onyx contains explicit descriptions of sexual acts. Some of the high-level actions in Onyx describe erotic actions like bondage and power exchange.
IF YOU ARE OFFENDED BY SEXUAL ACTIONS, BEHAVIOR, OR DESCRIPTIONS, DON'T DOWNLOAD THIS SOFTWARE!
If you are under the legal age of consent or live in a place where this material may be restricted or illegal, YOU SPECIFICALLY DO NOT HAVE A LICENSE TO OWN OR USE THIS COMPUTER PROGRAM. There is absolutely no warranty of any kind, expressed or implied. Use it at your own risk; the author disclaims all responsibility for any kind of damage to your computer, your car, your refrigerator, or to anything else.
By downloading Onyx, you certify that you are an adult, age 18 or over, and that you consent to see materials of a sexual nature.
download complete. you have the key. they have been waiting. do not delete dumpchk.exe.
He didn’t know who "they" were. He didn’t know what was beneath the East River. But the blue screen was gone. In its place, the server now showed a normal login prompt, as if nothing had happened.
The file was named release_them.bat .
Jansen pulled out his phone. The timestamp was 72 hours away. He looked back at the screen. The final line of the dumpchk report was not a debugging symbol.
Location 1: 40.7489° N, 73.9680° W (East River, beneath Roosevelt Island) Location 2: 38.8977° N, 77.0365° W (Washington, D.C., basement level 3) Timestamp: 2025-03-17 14:00:00 UTC
Except for one small change. In the root of the C: drive, a new file had appeared. Not memory.dmp. Not a log.
Jansen stared at the cursor blinking patiently, waiting for a command he was terrified to type. He had only wanted to fix a crash. Instead, he had just downloaded the trigger.
Jansen rubbed his eyes. Dumpchk was an ancient, forgotten utility—a relic from the Windows NT era that read crash dump files. It wasn’t something that invoked itself. He tried to run a standard repair, but every command was met with a soft beep. The keyboard was locked.
He hadn't typed that. The machine did.
CORRUPTION DETECTED IN MEMORY HOLE 0x7F. RUN DUMPCHK.EXE.
STACK TRACE: PID 4 (SYSTEM) IRP ADDRESS: 0xFFFFF880 ... UNKNOWN DEVICE: \Device\ShadowPersistence THREAD: T_WAIT_INDEFINITE MESSAGE: "LET THEM GO."
He pulled out his personal laptop, tethering it through a separate, air-gapped connection to a clean FTP mirror. His fingers moved on autopilot. He typed the command he hadn't used in a decade:
It was a reply.
The file was tiny. 47 kilobytes. It arrived in a second. He copied it to a floppy—the only medium the old server's OS still trusted—and walked it down to the sub-basement.
download complete. you have the key. they have been waiting. do not delete dumpchk.exe.
He didn’t know who "they" were. He didn’t know what was beneath the East River. But the blue screen was gone. In its place, the server now showed a normal login prompt, as if nothing had happened.
The file was named release_them.bat .
Jansen pulled out his phone. The timestamp was 72 hours away. He looked back at the screen. The final line of the dumpchk report was not a debugging symbol. download dumpchk.exe
Location 1: 40.7489° N, 73.9680° W (East River, beneath Roosevelt Island) Location 2: 38.8977° N, 77.0365° W (Washington, D.C., basement level 3) Timestamp: 2025-03-17 14:00:00 UTC
Except for one small change. In the root of the C: drive, a new file had appeared. Not memory.dmp. Not a log.
Jansen stared at the cursor blinking patiently, waiting for a command he was terrified to type. He had only wanted to fix a crash. Instead, he had just downloaded the trigger. download complete
Jansen rubbed his eyes. Dumpchk was an ancient, forgotten utility—a relic from the Windows NT era that read crash dump files. It wasn’t something that invoked itself. He tried to run a standard repair, but every command was met with a soft beep. The keyboard was locked.
He hadn't typed that. The machine did.
CORRUPTION DETECTED IN MEMORY HOLE 0x7F. RUN DUMPCHK.EXE. do not delete dumpchk
STACK TRACE: PID 4 (SYSTEM) IRP ADDRESS: 0xFFFFF880 ... UNKNOWN DEVICE: \Device\ShadowPersistence THREAD: T_WAIT_INDEFINITE MESSAGE: "LET THEM GO."
He pulled out his personal laptop, tethering it through a separate, air-gapped connection to a clean FTP mirror. His fingers moved on autopilot. He typed the command he hadn't used in a decade:
It was a reply.
The file was tiny. 47 kilobytes. It arrived in a second. He copied it to a floppy—the only medium the old server's OS still trusted—and walked it down to the sub-basement.
