A clever trick or stratagem. A cunning, crafty device or expedient. Wile. Trickery. Guile. Craftiness. Cunning. Ingenuity. Inventiveness. A skillful or artful contrivance or expedient. Subtle deception.
Subterfuge, deceit, deception, duplicity,
No matter what genre you write in, your plot needs some artifice to keep it real and maintain your readers’ interest. This word always makes me think of the antagonist in a story, due to its inferred connection with untruth, but there is no reason why your protagonist can’t use artifice as he makes his way through the story.
Maybe your protagonist needs to use artifice in order to prove a lie and to maintain his position of truth and honesty. A side character might use artifice in such a way as to manipulate the protagonists onto a certain path, whether for good or bad.
Artifice in all its forms, due to its position as part of normal human behaviour, is a necessary part of all fiction. To leave it out would be to take away a certain realism, a feeling of authenticity, from your story.