Character & Weapons
Caster Level is often lower than Character Level — a Paladin/Ranger's is Character Level − 3 (starting at 4th level), for example. Set it independently; it pre-fills spell entries below that scale with caster level (Divine Favor, Magic Weapon Greater, Wrath, Gorum's Armor...) instead of Character Level.
Character Level defaults this to full BAB (level, level-5, level-10...) — type over any box for a 3/4 or 1/2 BAB class, multiple iteratives, etc. The first box is also used as "BAB" everywhere else in the calculator (Power Attack scaling, etc.). Character Level also pre-fills other level-scaling fields (Sneak Attack dice, caster level, bard/paladin level...) when you add them from the catalog below.
Affects the handful of places that halve or ×1.5 a number (two-handed/off-hand Strength bonus, Power Attack/Deadly Aim two-handed damage). Off by default, matching the rules (round down); check it only if your table rounds up instead.
Ability Scores
Character
Character note only — doesn't hide or filter anything. Feats/traits from any sourcebook are always shown; check their own prerequisites to see if your character actually qualifies.
Deity-specific catalog entries (a handful of feats/traits/spells tied to worshipping one particular god) only show up once you've picked that deity here. Leave empty to see none of those — everything else is unaffected.
Weapon
Pick whichever ability your build actually uses for each roll — they don't have to match, and you can pick the same one for both (e.g. Weapon Finesse: Dex to attack, Str to damage; Agile/Slashing Grace: Dex to both; a bow: Dex to attack, none to damage; a thrown weapon: Str to both). The calculator doesn't check weapon-by-weapon eligibility, so choose what fits your character.
Target
Oozes, elementals, swarms, and incorporeal creatures are immune to critical hits and precision damage (Sneak Attack, etc.) in PF1e — picking one of those four automatically zeroes out Sneak Attack/Precise Strike above and flags Critical Damage below as not applicable. Constructs and (non-incorporeal) undead are NOT immune to crits/precision damage in PF1e, unlike 3.5e — don't gate those the same way.
Modifiers that only work against a specific enemy type (Favored Enemy, Bane, Challenge Evil, etc.) check this — set it before a fight and they'll switch on/off automatically. Leave it on "none" and they behave as before (always on while active).
Modifiers — pick from the catalog per category, or add a custom one
Spells and Other Effects boost the character in general. Weapon Effects (including enchanting spells like Magic Weapon) belong to a specific weapon or its ammunition — with Two-Weapon Fighting or Ranged selected as your Fighting Style, each Weapon Effect gets a small "Applies to" selector so you can mark which hand — or the ammunition — it's on.