From online medical dictionary at cancerweb
Placebo Effect: An effect usually, but not necessarily, beneficial that is attributable to an expectation that the regimen will have an effect, i.e., the effect is due to the power of suggestion.
Placebo: Any dummy medical treatment, originally, a medicinal preparation having no specific pharmacological activity against the patients illness or complaint given solely for the psychophysiological effects of the treatment...
It's really not an apt analogy for a video game because there does need to be an actual effect, the purpose is to distinguish between pharmacological vs. psychophysiological effects. The game mechanics are what they are, you thinking they may work differently doesn't make it so (unlike with your body), therefore it is impossible for there to be a psychophysiological effect.
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