I've read that prologues are acceptable if written well and are not blatant info dumps. But I've also heard they are a death knell in the minds of agents and editors who might be considering a work and think they are amateurish.
Dear Writer,
If you’re still in the process of writing, my recommendation would be to just write the story and ignore professional sensibilities. You need to finish the story and have fun doing it. Maintain your artistic integrity as long as possible, especially when you’re new.
If, however, you’re looking at a second or above draft and desire professional publication, consider the following:
Prologues are frowned at by professionals because they’re often unnecessary. A prologue should be relevant to the main plot of the story but should have significant thematic, perspectival, or chronological differentiation. If your prologue stars the main character, takes place around the time of the main story, or for all intents and purposes is a part of the main story, your prologue is your first chapter. To professionals looking for a decent reason to move on, this is a good one.
As with all the arts, any practitioner can bend the "rules" or flat-out violate them if they demonstrate enough panache, but known authors can get away with more than unknowns. Leading with a prologue puts an agent on yellow alert. How important is your prologue? Do a risk assessment.
If it’s at all possible for your prologue to become a proper chapter or for its points to be worked into the story, consider it.
"What do readers think?" The average reader will start at what you say is the beginning of the story trusting you to have done a good job until they find reason to think otherwise. The working professional will anticipate errors on the basis of their experience. I’d recommend you avoid the landmines inadvertently laid by others.
One of my books has a prologue and another doesn’t. In the book that has the prologue, GODDESS FROM THE MACHINE, the prologue is distanced chronologically and perspectivally from chapter 1.
If you’re self-publishing, do what you want.
Best,
DRM