The formula for a successfully applied status effect is as follows:

Caster:(Roll 1-100 + Talent bonus + Retribution score) > Target:(Armor % + Talent bonus + Perseverance score + Stat bonus)

Physical saves gain a bonus (the 'Stat bonus' mentioned above) equal to half the target's Constitution score. Magic saves gain a bonus equal to half the target's Wits score.

Saving Throws do not take place once a units armor is drops to 0. At that point, vanilla rules apply, and statuses will always take effect. However, all units regenerate to 1% Physical or Magic Armor shortly after being damaged down to 0. ABST grants all units this minor boost so that non-damaging spells with powerful effects (like Dominate or Polymorph) will always allow targets a saving throw.

Glass Cannon characters make no saves. The targets of casters with the Torturer talent are not granted saves against damage-over-time statuses.

With this mod installed, there are no more enemies with 0 Physical or Magic Armor. Enemies that previously had 0 in either type now have a very low amount equal to 5%-10% of their overall health.

Stat bonuses to armor saves and 1% armor regeneration can be disabled in-game. See 'Optional Changes' below.

Blessed characters make all saving throws and status attempt rolls with advantage, which means they roll twice and pick the higher number. Cursed characters make all saving throws and status attempt rolls with disadvantage, meaning they roll twice and pick the lower number. Situational advantage can also be granted by talents.

Gaining advantage from multiple sources will not grant additional rolls, but advantage scores do stack before they are compared. So, for example, a Blessed character (+1) also gaining advantage from Guerrilla (+1) will roll with advantage against a character only gaining advantage (+1) from Five Star Diner, and would make the same roll if that target was also Cursed (-1). Bosses have a natural advantage score of 1 on all saves and status attempts.

Perseverance: +1% to all saving throws per point invested. The armor restoration granted by Perseverance is now also triggered by additional disabling statuses like Sleep, Charmed, and Chicken Shape.
Retribution: +1% to all status attempts per point invested.
Leadership: Allies covered by the unit's Leadership Aura gain +4% to all saving throws per point invested.

On-hit weapon effects have been reworked for this mod, because vanilla weapon effects are underwhelming and not conducive to strategic play. Shocking Touch will always be a better choice than 25% to Shock.

Weapon effects now trigger every time that weapon is used, but they roll with reduced max values roughly based on what was once their chance to apply. So vanilla’s 15% to set Shocked is now 100% to set Shocked (No Armour), which rolls 1-15 instead of 1-100. In most other respects these rolls are treated as any other status attempt, though they can receive specific bonuses from a few talents. Weapon effects trigger after an enemy has regenerated to 1% armour, so they will never apply without having to pass a saving throw unless you disable enemy regeneration.

The tiers on weapon effects are as follows:
-Applies Status (No Armour): Roll of 1-10
-Applies Status (Low Armor): Roll of 1-20
-Applies Status (Half Armor): Roll of 1-30

ABST units will gain the following additional bonuses from talents, all of which are listed in the talent menu in-game and noted in the combat log as saves are attempted. Any temporary bonuses or inflicted penalties appear as status effects.

-Ambidextrous: +5 to all status attempts when your off-hand is free.

-Arrow Recovery: +5 to all status attempts with special arrows.

-Demon: Advantage on all status attempts applied by your surfaces.

-Duck Duck Goose: Advantage on all saves against surface-applied statuses.

-Elemental Ranger: Advantage on all weapon effect rolls with bows and crossbows.

-Escapist: Grants the following grab-bag of situational bonuses:
> Using Shields Up grants you advantage against the first hard disable (Frozen, Fear, Chicken, etc) before the start of your next turn.
> The chance of advantage granted by your Leadership aura also works offensively, granting the same percent-based advantage chance to status attempts made by affected allies.
> You make all saving throws with advantage when Flanked.

-Executioner: Advantage on your next status attempt that turn after dealing a killing blow.

-Far Out Man: +5 to weapon effect rolls made with ranged weapons or staff of magus projectiles.

-Five Star Diner: Advantage on your next physical save after eating. Advantage on your next magic save after drinking alcohol. These effects can be set out of battle and persist until used up.

-Guerrilla: Advantage on status attempts made from Sneaking or Invisibility. This effect also applies to your next attempt after starting a turn in smoke.

-Hothead: +3 to all status attempts when at full health.

-Ice King: Your staff of magus projectiles make enemies save with disadvantage against the next incoming magic effect.

-Leech: Blood heals grant advantage to your next physical save or physical status attempt, whichever comes first.

-Living Armour: +5 to magic saves. Advantage on all saves against Necrofire.

-Mnemonic: Advantage on all saves against Silenced or Disarmed.

-Morning Person: Advantage on your first save against a hard disable (Stun, Charm, Sleep, etc) per combat encounter. Resets on death.

-Opportunist: +5 to weapon effect rolls made with melee weapons.

-Parry Master: Each attack made or weapon skill cast while dual wielding increases your chance to set physical or magic statuses by 3 for the rest of the turn: physical statuses after attacking with melee weapons, magic statuses after attacking with wands.

-Picture of Health: +5 to physical saves. Advantage on saves against decaying.

-Savage Sortilege: Grants advantage to your attempts to set Cursed or drain Source. (See 'Optional Tactician Challenges' for a new way to obtain the Curse spell.)

-Slingshot: Grants the following grab-bag of situational bonuses:
> Your Flurry attacks make enemies roll with disadvantage on their next physical save.
> Your All-In attacks make enemies roll with disadvantage on their next status attempt.
> +10 to all status attempts with grenades; -10 when targeting allies.

-Unstable: +5 to set Blind, Crippled, Cursed, Deaf, Decaying, Disarmed, Diseased, Exchange, Fireblood, Infected, Nullified, Shackled, Silenced, Slowed, and Weak, plus 5 for each of those statuses your target already has.

-Walk it Off: +3 to all saving throws.

-What A Rush: Advantage on your next status attempt after starting a turn under half health.

A number of optional difficulty tweaks can be enabled by interacting with a stationary item called the Hookah of Strife. This object can be found in the Fort Joy arena by the ladder and in the hold of the Lady Vengeance. It opens a dialogue menu that can do the following:

-Grant or remove flat saving throw bonuses described in-game as 'resolve points' to all non-party units. These are added 5 points at a time.

-Give or remove a natural advantage score of 1 to bosses, meaning they make all saves and status attempts with that baseline 1 advantage. This setting is on by default.

-Turn off saving throw bonuses from Wits and Constitution.

-Prevent or enable enemies regenerating to 1% Physical or Magic Armour a few seconds after being damaged down to 0. This setting is on by default.

-Exchange a character's Bless skill for Curse or Curse skill for Bless. (Yes, this violates plot conventions but it enables too much tactical richness to pass up.)

Status effects applied by auras in the vanilla game proc on short timers, meaning they can be attempted again and again indefinitely over the course of a single turn. Because ABST's percentage rolls make this mechanic so easily abusable, aura statuses are now applied when the aura skill is cast, and at the start and end of the aura-haver's turn.

Statuses inflicted by AOE domes are applied through armor with no saving throw. These are not present in the base game but found in some class mods.