From the publisher's webpage:
There are monsters out there.
Most people don't believe in them, but they're real. Mostly, when someone finds out that monsters are real, that's just before they die.
But some people are mean enough, smart enough, crazy enough, or hurt enough, that they live. They go on a crusade to kill the monsters.
That's who you are.
It could be that you make a stand and defend your hometown from everything evil that comes there.
It could be you take to the road and go hunt them down.
It could be you have magic powers.
It could be that your name came up in prophecies thousands of years ago.
The one sure thing is you aren't gonna go back to your old, safe life.
Monster of the Week is a pen & paper roleplaying game in which you are monster hunters in a world much like ours.
(user addition)
This is the beta version of the core rulebook, released to supporters of the IndieGoGo campaign.