General:
* Lure: This is a very common synonym, often used in the context of attracting something.
* Bait: This is used specifically for attracting animals or people for trapping.
* Dummy: This implies something fake or artificial used to mislead.
* Allure: This emphasizes the attractiveness of the decoy, making it seem desirable.
* Attractor: This is a neutral term for something that draws attention.
* Distraction: This focuses on the decoy's ability to divert attention from something else.
Specific to deception:
* Sham: This refers to something that is fake or pretending to be something it is not.
* Ruse: This is a clever trick or strategy used to deceive.
* Feint: This is a deceptive movement designed to mislead an opponent.
* Blind: This implies something that hides the real target from view.
Other options:
* Diversion: This is used when the decoy is intended to draw attention away from something else.
* Substitute: This is used when the decoy is used in place of something else.
* Placebo: This is used when the decoy is used to make people believe something is happening when it is not.
The best word to use will depend on the specific context.