First PC sheet, WIP

module/documents/roll.mjs

@@ -7,6 +7,15 @@ import { SYSTEM } from "../config/system.mjs"
 export default class PrismRPGRoll extends Roll {
   static CHAT_TEMPLATE = "systems/fvtt-prism-rpg/templates/chat-message.hbs"
 
+  /**
+   * Calculate D&D 5e style ability modifier from ability score
+   * @param {number} abilityScore The ability score value (3-18+)
+   * @returns {number} The ability modifier
+   */
+  static getAbilityModifier(abilityScore) {
+    return Math.floor((abilityScore - 10) / 2)
+  }
+
   // Getters for roll data
   get type() {
     return this.options.type
@@ -89,17 +98,40 @@ export default class PrismRPGRoll extends Roll {
     switch (options.rollType) {
       case "characteristic":
         options.rollName = options.rollTarget.name
-        // Value already set in actor.mjs
+        // Calculate D&D 5e modifier from characteristic value
+        options.rollTarget.value = this.getAbilityModifier(options.rollTarget.value)
+        break
+
+      case "sub-attribute":
+        options.rollName = options.rollTarget.name
+        // Sub-attribute value is already a modifier (calculated in prepareDerivedData)
         break
 
       case "challenge":
-      case "save":
         options.rollName = game.i18n.localize(`PRISMRPG.Label.${options.rollTarget.rollKey}`)
         break
 
+      case "save":
+        options.rollName = `${game.i18n.localize(`PRISMRPG.Label.${options.rollTarget.rollKey}`)} Save`
+        // Calculate D&D 5e saving throw: ability modifier + proficiency bonus
+        // Get the characteristic value from rollTarget
+        const charValue = options.rollTarget.characteristicValue
+        const abilityMod = this.getAbilityModifier(charValue)
+        const saveBonus = options.rollTarget.saveBonus || 0
+        // Store separate values for display
+        options.rollTarget.abilityModifier = abilityMod
+        options.rollTarget.saveProficiency = saveBonus
+        // Add the save bonus (proficiency) stored in saves
+        options.rollTarget.value = abilityMod + saveBonus
+        break
+
       case "skill":
         options.rollName = options.rollTarget.name
-        options.rollTarget.value = Math.floor(options.rollTarget.system.skillTotal / 10)
+        // D&D 5e style: ability modifier + proficiency bonus
+        const skillCharValue = options.rollTarget.characteristicValue
+        const skillAbilityMod = this.getAbilityModifier(skillCharValue)
+        const proficiency = options.rollTarget.proficiencyBonus || 0
+        options.rollTarget.value = skillAbilityMod + proficiency
         break
 
       case "weapon-attack":