diff --git a/apps/web/src/engine/tick.ts b/apps/web/src/engine/tick.ts
index c8b42a4..240edab 100644
--- a/apps/web/src/engine/tick.ts
+++ b/apps/web/src/engine/tick.ts
@@ -246,7 +246,14 @@ export const computeEssencePerSecond = (state: GameState): number => {
 /**
  * Computes the party's total combat power, applying all active multipliers
  * (upgrades, prestige, equipment, set bonuses, echo, crafted, companion).
- * This mirrors the server-side calculatePartyStats in boss.ts.
+ * This mirrors the server-side calculatePartyStats in boss.ts and is the
+ * single source of truth for all combat-power checks in the client:
+ * - Displayed as "Combat Power" in the resource bar
+ * - Displayed as "Party DPS" in the boss panel
+ * - Used to gate quest availability
+ * Note: the active companion's bossDamage bonus is intentionally included
+ * here, as it applies to the full combat power calculation (boss fights and
+ * quest gating alike), matching the server-side behaviour.
  * @param state - The current game state.
  * @returns The total party combat power.
  */