Your investigator will need a:

• Name
• Archetype
• Occupation
• Weakness
• Strength

Archetype
(You could be solely one, or be a combination of two or more of these.  Very flexible.)

Guardian - Defender of humanity, combating the forces of the Mythos.  A dutiful, selfless, and protective hunter.
Seeker - Always looking to learn more about the world and the Mythos.  Researching old lore, exploring new places, and studying new creatures.
Mystic - Attracted to the arcane forces of the Mythos.  Developing spell-casting abilities or otherwise learning to manipulate the forces of the universe through magical talent.
Rogue - Self-serving, wily, and opportunistic.  Eager to find ways to exploit your current situation.
Survivor - Everyday person who got caught in the wrong place and the wrong time, simply trying to survive.  An ill-prepared and ill-equipped underdog who will rise to the occasion when your life is threatened.

Occupation
(This may not be a traditional, paid career.  It could also be a life pursuit, or just the current circumstances of your life.  These are just some examples.  Please don't limit yourself to only these.)

Shaman, Redeemed cultist, Priest, Actress/Actor, Drifter, Athlete, Urchin, Ex-con, Bounty hunter, Bootlegger, Librarian, Professor, Researcher, Boxer, Soldier, Rookie cop, etc, etc, etc.

Weakness
(Could be a madness, an enemy, a responsibility, a curse or pact, a character flaw (physical, mental, or social), an unfortunate event. These are just some examples.  Please don't limit yourself to only these.)

Stalked by hooded figures, A voice of the messenger (by curse or pact), Been caught red-handed, Lodge "debts", An unsolved case, A mysterious tome, You bought something in blood, Must smite the wicked, Dark future, Pursued by figure of evil, etc, etc, etc.

Strength
(Could be a boon, an asset, an specific item or weapon, a personal talent, skill, or insight, an allied person or animal, a spell, an amazing experience.  These are just some examples.  Please don't limit yourself to only these.)

Family inheritance, Customized firearms, Analytical mind, Search for the truth, A sole survivor you rescued, Symbol of Righteousness, Mystifying song, The codex of ages, A loyal hound, A musical instrument, etc, etc, etc.

STRENGTH AND WEAKNESS

These character descriptions primarily add story flavor, the chance for heroism, tragedy and/or comedy, and plot hooks.  But, they also have a role to play mechanically:

If your Strength relates to a roll being made, you can gain a bonus to the roll; +5 to +20, depending on circumstances and how directly it relates.  If your Weakness relates to the roll, you might get a similar penalty when rolling.  Naturally, you guys will probably notice the Strength bonus possibility more often, and I'll probably notice the Weakness possibility more often, but anyone can call out for one or the other, even for other players.  The more directly you can tie it into your roleplaying, the better chances of receiving the Strength bonus.  And there may be times I pull on your Weaknesses to heighten the struggle.  Also note, I'm less likely to call out the Weakness for roll penalties if I'm seeing the Weakness being roleplayed out flavorfully in the story.
This message was last edited by the GM at 15:08, Thu 03 Mar 2022.

Numbers, numbers, numbers... (Is this working?)

Each investigator will use 4 essential Skills when making rolls to overcome challenges.

Willpower - Horror checks, Guts, Faith, Curiosity, Adventurous, Steadfast, Fearless, Prescient intuition, etc.
Intellect - Investigate clues, Parley with others, Perception, Research, Deduction, Curiosity, Cunning, Interpretation, Sharp vision, etc.
Combat -  Attack/ Overpower/ Assault others, Stunning blows, Able-bodied, Steadfast, vicious blow, Brute force, etc.
Agility -  Evade others, Manual dexterity, Speed, Dodge, Able-bodied, Cunning, Riposte, Expeditious retreat, etc.

You get 200 points to allocate among these 4 Skills however you choose.  Maximum Skill is 75 for now.  Minimum score 10 (yes, you still have to pay for those measly 10 out of the 120 point pool).  20-40 would be considered your average, empty NPC score.

This is a percentile dice game.

In order to gain a basic, minimal success at any Skill check, you have to roll percentile dice and get less than or equal to your skill value.  So a high skill trait means you're more likely to roll under it and succeed.  Circumstances of the story may give you a bonus or a penalty to this roll.  Investigators may also work together to give each other bonuses to rolls if circumstances allow.

Rolling under 1/2 of your skill value gives you a better success.
Rolling under 1/5 of your skill value gives you an extraordinary success.
Rolling 00-05% is an automatic success, no matter your skill or modifiers.  (The Mythos can suck it!)
Rolling 95-100% is an automatic failure, no matter your skill or modifiers.  (The Mythos rises!)
This message was last edited by the GM at 15:17, Sun 06 Mar 2022.

Life, Death, and Horror

To survive your adventures of Arkham Horror, you need both a strong body and a strong mind.  These will be represented by your Health and Sanity Traits.

Health - Hit points, Physical durability, Pain resistance etc.
Sanity - Horror points, Mental durability, Comfort level, etc.

You get 140 points to allocate between these two traits.  Maximum trait is 90 for now.  Minimum score 10 (yes, you have to pay for those 10 points out of your 140 point pool).  Most average, empty NPCs will have a mixed bag of between 20-40 for each Trait.

Health and Sanity damage will generally be dealt or healed 5-10 points at a time, though it could be higher, depending on the circumstances.

The first time either your Health or Sanity Trait reaches zero, you are NOT dead!

Instead, you take a point of permanent Trauma (either Physical or Mental, depending on which trait reached zero).  Then work with the GM (me) to define that trauma in terms of a new Weakness to include in your roleplay.  Lastly, restore that trait from zero to 1/2 its original score, and continue playing in the current scene with no other restrictions.

If the same Trait reaches zero a second time in the same chapter, you are NOT dead!

Instead, you gain another point of permanent Trauma (and an additional associated Weakness), and will be somewhat incapacitated for the rest of the current scene.  You'll still be present, but you'll mostly be flavor posting your injury or madness (so, still lots of room for tragedy and/or comedy to be played out).  You will NOT be able to make any skill checks, fight monsters, investigate clues, etc.  Once the action of the current scene resolves and you have a moment to catch your breath, restore that Trait back up to 1/5 its original score and you can continue playing through the chapter normally.

If the same Trait is reduced to zero a third time in same chapter...I'm sorry, my friend.

This investigator is out (NPC status) for the rest of this chapter.  You can give them up for dead, permanently retire them, or send them to the appropriate care facility (hospital/ sanitarium) to recuperate over the course of the following chapter.  Either way, in order to keep playing, you'll have to introduce a new investigator.  (I don't anticipate this happening often, but I want to acknowledge the possibility because this is a game of horrors and the threat of real death must be present for the horror to be real.  Of course, there are fates worse than death...)

At the end of each chapter, everyone is restored back to their original/ max Health and Sanity Traits.  Any permanent Trauma Weaknesses are retained, but they can potentially be reduced or removed through roleplay efforts in subsequent chapters.
This message was last edited by the GM at 22:00, Tue 01 Mar 2022.

The Accoutrement of the Occult

Our first chapter stays pretty self-contained; all the action happens within one house over the course of one night.

All you'll need to start out with is a weapon of some sort and any basic items people would normally carry on them.  You don't have to make an exhaustive list for this, but a sentence or two giving a general idea of what kind of stuff your investigator keeps in their pockets or handbags would be nice.

Your investigator will eventually need all the usual stuff that human beings need.  A home, possibly a vehicle, possessions, equipment, supplies, some cash, at least 1 weapon of some sort, and connections with other humans (family, work, community, friends, rivals, etc.)  I'm not too particular about how this all gets hammered out, and a lot of it we can develop together as the story progresses and the characters grow.  For the most part, if it's a reasonable fit with the archetype, occupation, weakness, and strength you've given your character (and the norm of the 1920's), you can probably have it.  (If this turns out to be too vague or needs to be moderated against player abuse, then we'll start using the Credit Rating mechanic from Call of Cthulhu 7e, but we'll get through at least this first chapter before evaluating and making that decision.)

Leveling up

As we play more (aka. gain experience, level up, achieve victories, manage to survive, etc.) I'll make sure you get opportunities to get more specific and directly helpful items, allies, and other beneficial assets.  You'll also get more points to put into Skills and Traits and the chance to reduce or remove the various Weaknesses you'll gain through Trauma.
This message was last edited by the GM at 16:47, Wed 02 Mar 2022.

CHARACTER SHEET

Investigator name:

[A sentence or two describing your vision of each of the following:]

Archetype(s):

Occupation(-ish):

Weakness:

Strength:

[Here's the numbers section:]

Willpower:

Intellect:

Combat:

Agility:

Health:

Sanity:

[Other stuff we'll flesh out later, if we all survive the first chapter and still like each other at the end.  But if you've got some ideas about this stuff, please share.]

Trauma(s):

Equipment:

Whole, Half, and Fifth?

Call of Cthulhu 7e uses half and fifth to grant their version of additional degrees of success for good rolling, and I kinda like it, so I'm keeping it.  Sometimes, a particularly difficult task may require a success by half or fifth to get even the basic, minimum successful outcome.  Sometimes succeeding by half or fifth will give you a bonus, such as extra damage or more detailed information.

Here's a handy chart, since I hate math and want these numbers to be easy for everyone.  (The fifths, especially, give me trouble for some reason.)

Base Value (current max)
     Half value (1/2 max)
           Fifth Value (1/5 max)

1     0     0
2     1     0
3     1     0
4     2     0
5     2     1
6     3     1
7     3     1
8     4     1
9           1
10    5     2
11          2
12    6     2
13          2
14    7     2
15          3
16    8     3
17          3
18    9     3
19          3
20    10    4
21
22    11
23
24    12
25          5
26    13
27
28    14
29
30    15    6
31
32    16
33
34    17
35          7
36    18
37
38    19
39
40    20    8
41
42    21
43
44    22
45          9
46    23
47
48    24
49
50    25    10
51
52    26
53
54    27
55          11
56    28
57
58    29
59
60    30    12

This message was last edited by the GM at 16:50, Wed 02 Mar 2022.