Implement most of shield functionality using the armour implementation as a backbone

module/Apps/ActorSheets/HeroSummaryCardV1.mjs

@@ -143,6 +143,7 @@ export class HeroSummaryCardV1 extends GenericAppMixin(HandlebarsApplicationMixi
 	static async prepareArmor(ctx) {
 		ctx.armours = {};
 		const equipped = ctx.actor.system.equippedArmour;
+		const shield = ctx.actor.system.equippedShield;
 		const defenses = ctx.actor.system.defense;
 		for (const slot of Object.values(gameTerms.Anatomy)) {
 			const item = equipped[slot];
@@ -150,9 +151,16 @@ export class HeroSummaryCardV1 extends GenericAppMixin(HandlebarsApplicationMixi
 				name: item?.name ?? ``,
 				uuid: item?.uuid ?? ``,
 				defense: defenses[slot],
-				shielded: false,
+				shielded: shield?.system.location.has(slot) ?? false,
 			};
 		};
+
+		ctx.shield = {
+			name: shield?.name ?? ``,
+			uuid: shield?.uuid ?? ``,
+			bonus: shield?.system.protection ?? 0,
+		};
+
 		return ctx;
 	};
 

module/data/Actor/Hero.mjs

@@ -165,7 +165,8 @@ export class HeroData extends foundry.abstract.TypeDataModel {
 	};
 
 	get equippedShield() {
-		return null;
+		const shields = this.parent.itemTypes.shield;
+		return shields.find(item => item.system.equipped);
 	};
 
 	get defense() {
@@ -175,7 +176,13 @@ export class HeroData extends foundry.abstract.TypeDataModel {
 			defenses[slot] = armour[slot]?.system.protection ?? 0;
 		};
 
-		// TODO: add shield defenses
+		const shield = this.equippedShield;
+		if (shield) {
+			for (const location of [...shield.system.location.values()]) {
+				const slot = location.toLowerCase();
+				defenses[slot] += shield.system.protection;
+			};
+		};
 
 		return defenses;
 	};

module/hooks/init.mjs

@@ -32,6 +32,7 @@ Hooks.once(`init`, () => {
 	// #region Datamodels
 	CONFIG.Actor.dataModels.hero = HeroData;
 	CONFIG.Item.dataModels.armour = ProtectorData;
+	CONFIG.Item.dataModels.shield = ProtectorData;
 	CONFIG.Item.dataModels.weapon = WeaponData;
 	// #endregion