Monster of the Week is an exceptionally simple system to play by roleplaying standards, but it helps to have some idea of how to play it. Not everyone might have access to the basic rules. So, here we'll include the basics needed to play.
First of all, not every situation requires a roll at all. If there is no dramatic consequence to failing a roll it won't happen. For example, cooking dinner isn't a major issue - if you have good food or bad will rarely impact the plot. Cooking to impress your one true love, on the other hand, might require some dice rolls...
Now, when you do roll, almost every roll in the Monster of the Week is based on a 2d6 with an addition or minus based on your statline. If your total score is 6 or less, you fail to achieve your roll. If your roll a 7-9 then you succeed, but often only just barely or in a way that will have consequences. On a 10 or higher you succeed, usually in impressively competent fashion.
In addition, each Hunter starts with 7 points of Luck. You can burn a use Luck to negate damage done or to change a roll so it counts as a 12. However, there are very ways to get Luck back once it's spent...and once it's all gone bad things tend to happen to the unlucky who hunt monsters.
Of course, there isn't much point at rolling dice for no reason. Each Hunter has a set of moves they can use in various situations. The basic set of moves available to every Hunter can be found on this hand Hunter Reference Sheet and also lists the Advanced version of each Move, which can be unlocked as a level up option. In addition, each Playbook has it's own unique moves and abilities, as detailed on the sheet.
Combat is pretty much like the rest of Monster of the Week - you'll be rolling 2d6 and adding a modifier to see how well a Move goes. The most common move will be Kick Some Ass, which would be 2d6 + Tough, but might involve any of them.
Several moves, especially Kick Some Ass, will inflict damage on a creature. A basic punch will inflict 0 harm, temporarily stunning a foe rather than hurting them, but each weapon and attack has a set damage.
A wise Hunter will probably wear armour. Armour simply reduces the damage an attack inflicts. If an attack is armour piercing, it will ignore that armour.
Most Hunters can take a total of 7 harm before going. They can suffer 3 harm without suffering major issues. After that the injuries will take longer to heal, and become unstable, requiring medical or magic aid to stop them getting worse. Minions, monsters and bystanders will be able take varying amounts of damage, depending.
Unlike the traditional turn based system in many roleplaying games, Monster of the Week simply has a reaction occur each time a player takes a turn in combat. This may be the person they're attacking wounding them back, an enemy fleeing, casting a spell, or something else. These events are entirely narrative, and will succeed unless a character intervenes.
Leveling up is a pretty simple system. Each time a character earns 5 Potential, they trade those 5 in for a level up and go back to zero. Certain moves can grant Potential, such as the Expert's Often Right Move. At the end of a Mystery each player will also earn 1 or 2 potential. The most common way to earn Potential is roll a 6 or under - each time you fail you Mark Potential. Hence why can't roll to walk down the street on a sunny afternoon.
Of special note is that once a character has leveled up 5 times you gain access to the advanced options listed on each Playbook.