Math Guide

Event Checks[]

Most events are checking your stats in this way:

{ Your checked Stat } vs { roll from 1 to 12 } + { threat level modifier }. Bigger value wins, draw is counted in player's favor.

Locations that you investigate can have varying threat levels that might grow during the game. There are 4 threat levels:

SAFE = no modifiers.
LOW = +1 to stat checks
DANGEROUS = +1 to stat checks & more Stamina/Reason penalties
DOOMED = +2 to stat checks & more Stamina/Reason penalties & more Doom for investigating

Game difficulty affects threat level
Try to memorize (look up, or guess) what stat will be checked. Its not always obvious but most of the time you can guess
Check location threat level
Manage your stats (get followers, acquire items, treat injuries, etc)
Having suitable perks or items can help you evade some skill checks in events. Cover your weak stats with right items and perks

Hit chance is partially based on your level, partially on enemy power and your weapon stat.

Your hit chance = { weapon stat } + { 10% * your level } - { enemy power }

Oh boy, here we go. First, the things you need to know:

Stats do not affect every aspect of battle. Only when action scales with certain stat, this stat will affect speed of this action. Only that.
Only certain actions are scaling: Attack, Strong attack, Dodge, Brace, Combat Skill, Shoot, Listen Ramblings (unique action vs Doll Nurse).
There are "general" speed modifiers of action groups (Offensive, Defense, Spiritual, Support). This boosts accessible only by: smoking cigarettes, perks (Fast Swimmer Adrenaline, Fame), follower boosts, some items (like Karukosa Mask).Formula for action time:

Action time = { base time } x { general speed modifiers } – { scaling } x { stat }

Explanation of the above example:

Base action takes 80t, general modifier is 0.9, Dexterity is 8, Scaling value for normal "Attack" action is 3. So, (80 * 0.9) – (3 * 8) = 48

Example of how time cost for various actions scales depending on stat
Stat value -->	Base time	1	2	3	4	5	6	7	8	9	10	11	12	Scaling
S.Knife normal attack	80	77	74	71	68	65	62	59	56	53	50	47	44	-3*Stat
S.Knife strong attack	120	116	112	108	104	100	96	92	88	84	80	76	72	-4*Stat
Brace	160	155	150	145	140	135	130	125	120	115	110	105	100	-5*Str
Dodge	160	150	140	130	120	110	100	90	80	70	60	50	40	-10*Dex
Combat Skill	100	95	90	85	80	75	70	65	60	55	50	45	40	-5*Knw
Listen/Shoot	120	115	110	105	100	95	90	85	80	75	70	65	60	-5*Per

General modifiers are applied before scaling. So they are very good with scaling.
Multiple general modifiers are multiplicative. As example for Aiko offensive actions, her innate speed buff multiplies by her Fast Swimmer perk effect: 0.9 * 0.85 = 0.76 (truncated).
Everything is truncated in your favor. Rejoice.
Scaling is fixed per action. So slow weapons scale worse and suck.
Getting Spiritual actions speed up will help only if you already scaled well with Strength or Dexterity to add defensive action to Clap\Bow ritual. Even after that, there aren't many ghost encounters, you need to guess the ritual only once per run, and not all ghosts will furiously bite you while you guessing.