I am not saying eliminate death from the game but have some means of separating a mere punch to the gut or a schoolyard brawl from an actual lethal conflict. Honestly giving 1 harm for a twisted ankle, getting hit with a dodge ball or a minor scrape from a trip dosen't make sense to me. Harm should be for only things that are life-threatening injuries. For any other kind of injury, Strings and/or conditions would be better used. Of course this isn't the most lethal system I've seen. The Hood, for instance, you have 3 health levels, Up  (Healthy), Down (Dying) and Out (Dead). Most physical harm just does conditions to those effected and has game effects but when someone busts a cap in your ass your character is pretty much either on the ground bleeding out or dead. It may be laugable for a vampire to die from a gunshot wound but monsters in this game are barely more competent than normal people and that's the theme I suppose.

One thing I am thinking is that players do not instantly die at 0 HP but can survive on the brink of death for a number of rounds equal to their constitution modifier. This helps in many cases as Good Clerics can gain XP by saving a character on the brink. It also gives more suitability and realism as in most editions of D&D there is a negative HP survival. Would this be a viable option?

Is it ok to make some moves not allowed in the game. One of the most broken moves is the "Smite" move of the Divine. Or what I call "The Magic Bullet for Every Monster". One of the main parts of Monster of the Week is to find and exploit the weakness of a monster to defeat it. A Divine Playbook with smite pretty much cuts this out as the PC's merely have to beat down the Monster's harm in a fight and have the Divine do the finishing blow, totally removing an important part of an investigation. So in my games I remove the Smite ability from play as makes an important part of the game a moot point.

I am thinking about in-acting a house rule called a "Critical Hit". Basically if a player rolls a natural 12 on the dice, they get something on top of the 10+ result on the chart. Here is a breakdown of critical hit bonuses. Note this only applies if you roll a 12, not if you get 12+ from skill bonuses.

Act Under Pressure: You confidently and courageously accomplish what you set out to do. You get a +1 forward on your next roll.

Help Someone Out: You work in sync with those you are helping. You give them a +2 bonus to their roll.

Investigate a Mystery: You gain an additional hold from the list (Hold 3)

Kick Some Ass: You can either chose 2 extra effects from the 10+ chart or pick from the list below. These are a follows:

1. Suffer no harm (Completely avoid a counter-attack)
2. Shut down a monster move or attack ability. You must describe how you are doing this. (Such as cutting off a claw, breaking the monster's teeth, or disorienting the monster by a blow to the head). The keeper should refrain from allowing the monster to use that ability unless they take a turn to recover.
3. Strike a crippling blow. You inflict a condition on the monster relevant to the form of the attack.

Manipulate Someone: You utterly convince the person to do what you want. They will do it for you, no strings attached. For hunters, they get a +2 forward to do what you ask.

Protect Someone: Chose 2 extras from the 10+ chart.

Read a bad situation: You can either hold 4 from the list or get a +2 forward on the first attempt to act on this information (+1 for further attempts).

Use Magic: You channel a massive amount of magical power. You can either take a +1 forward on your next Use Magic roll or use this option. Chose 2 magical effects from the Use Magic list. However if you do so, you get a glitch as though you rolled a 7-9 due to some form of magical overload.

Thanks for your advice on the game. This is my first time running Monsters of The Week so thinking of the best way to run it is difficult. The only Appoclapse Engine game I've played before was Dungeon World after all.  As for the Pregens, I've already made their character sheets and spent a while searching the net for images and building the sheets picking what would fit the character's best for their types. I might however just leave the history blank and let the PC's develop their own histories for the Pre-Gens, just to give them some creative control.

In the future I will be running a Monsters of the Week One Shot at a gaming convention. I really want to use Pre-Gens rather than do on the spot character creation as I already have a background prepared for each of the Hunters. The game slot is at most 4 hours so I doubt I can run the adventure, explain the game and allow players to create their own characters.

Anyway, the variant I'm doing with this setting is that I'm basing the world on a JRPG that has not been translated into English called "Beast Bind". Of course since I don't read Japanese my knowledge of the setting is based off of a translated Wiki page and a Visual Novel based in the universe (also which I cannot understand, but as they say pictures speak a thousand words).

The Major PC's are:

The Chosen, Hideaki Komatsu: The heir to his branch of the Komatsu family, an honorable family with Samurai traditions who in Ancient Japan fought against Oni and other evil spirits. He bears the family legacy, the Komatsu Katana, a magical blade that can slay even ghosts with its edge. He now tries to hunt monsters while balancing his life as a high school student.

The Expert, Hayato Mochizuki: The loyal retainer of the Komatsu family. An educated man skilled in combat arts and well educated in the the lore of the supernatural. He has taken up the mentorship and training of Hideaki and assists him in the hunt of the monsters that lurk in the shadows.

The Murdane, Ran Nakamura: A childhood friend of Hideaki and a tomboy whose always looking for adventure. She found out Hideaki's secret and insists on helping him out in the hunt for monsters. She's confident and impulsive and cares a lot for Hideaki and competes for his attention, especially against Katsuri Moriko.

The Monstrous, Katsuri Moriko (Mori): Once a social butterfly at Waseda High School, Katsuri got attacked and nearly killed a evil vampire one night but was saved by hunter team. During the fight she was accidently sprayed by the vampire's blood, swallowing it and becoming a vampire herself. She now is a rookie vampire, trying to control her thirst for blood while at the same time helping the team on the hunt. She also has a crush on Hideaki, much to Ran's chagrin.

The Spooky: Sayomi Inoue: A freshman at Waseda high school and a heir to a bloodline of ancient Japanese mystics. Sayomi is often plagued by visions of the supernatural and struggles to control her growing magical powers. Still her magical abilities are invaluable to the team and have helped out the group with a number of missions. She is curious about the Chosen and sticks close to him to see how his actions will affect the flow of fate.

The Flake: Nobaru Arakaki: A genius computer hacker who has become somewhat unhinged after discovering that monsters exist in the world. His brain works on overdrive a lot of the time and he can often come to grandiose conclusions. He is the information broker and logistics officer of the group, often taking a supporting role in the hunt. He is attracted to Katsuri and is fearful of Sayomi, suspicious she may at any time go off the deep end.

The Initiate: Quintin Alexander: A Foreigner from Italy, who has taken up the role as a local priest at a Catholic church in the city. He works for the Burial Agency, a branch of the church dedicated to hunting and killing monsters. However as the church has a weak influence in Japan, he is one of the few field operatives in Japan, meaning an alliance with the chosen was a smart move on his part. He is skilled with medieval weapons and possesses magic that can call on the powers of godly miracles. 

The Professional: Akane Tokiwa: A former police officer, who encountered the supernatural in the line of duty. She retired from the force and joined the JSID (Japanease Supernatural Investigation Division), a black-opp government agency that investigates supernatural activity and fights it through the use of advanced technology. Crossing paths with the Hunter, she now begrudgingly works with the group from time to time, or at least whenever their goals overlap.

The Wronged: Daichi Hamada: A one time construction worker and family man, Daichi lost his family to the monsters years ago. He now has a vendetta to hunt down the Oni and slay them without remorse. He helps bring some muscle in combat to the hunt but he is obsessive and unstable and does not trust Sayomi and Katsuri, almost measuring them to the real monsters that he hunts.