A mechanic is not a system. A mechanic is a verb. If you can't say it in three words, you don't have it yet.
The core problem
Most design docs describe mechanics as paragraphs. "The player has a stamina bar that depletes when performing certain actions, and can be replenished by…"
What the good ones do
A shipping mechanic reads as a verb the marketing team can put on a Steam page.
- "Parry to steal."
- "Shrink to fit."
- "Draw to move."
That's the mechanic. Everything after it, timing windows, forgiveness, resource costs, is tuning.
The three-channel rule
A verb without feedback is a bug. Every mechanic gets specified in three channels:
- Visual, what the screen does.
- Audio, what the player hears in the first frame.
- Haptic, what the controller does.
If any channel is missing, the mechanic feels broken even when it "works."
The tell
Watch a stranger play for 90 seconds without telling them anything. If they don't do the verb on purpose within that window, either the verb is too weak or the feedback isn't landing.
Draft one with the Mechanics Designer.