diff --git a/dGame/dComponents/MissionOfferComponent.cpp b/dGame/dComponents/MissionOfferComponent.cpp
index 45fb32dcd..f754e52fb 100644
--- a/dGame/dComponents/MissionOfferComponent.cpp
+++ b/dGame/dComponents/MissionOfferComponent.cpp
@@ -136,6 +136,21 @@ std::vector<uint32_t> MissionOfferComponent::ParseRandomPool(const std::string&
 	return pool;
 }
 
+bool MissionOfferComponent::HasMission(const uint32_t missionId) const {
+	for (const auto& offeredMission : this->offeredMissions) {
+		if (offeredMission.GetMissionId() == missionId) return true;
+
+		// A random mission stands for the missions in its pool
+		CDMissions info{};
+		if (!Mission::IsValidMission(offeredMission.GetMissionId(), info) || !info.isRandom) continue;
+
+		const auto randomMissionPool = ParseRandomPool(info.randomPool);
+		if (std::ranges::find(randomMissionPool, missionId) != randomMissionPool.end()) return true;
+	}
+
+	return false;
+}
+
 const OfferedMission* MissionOfferComponent::GetOfferedMission(const uint32_t missionID) const {
 	const auto offered = std::ranges::find_if(offeredMissions, [missionID](const OfferedMission& other) { return other.GetMissionId() == missionID; });
 	return offered == offeredMissions.end() ? nullptr : &*offered;
diff --git a/dGame/dComponents/MissionOfferComponent.h b/dGame/dComponents/MissionOfferComponent.h
index b33ba47f8..fc6a76c50 100644
--- a/dGame/dComponents/MissionOfferComponent.h
+++ b/dGame/dComponents/MissionOfferComponent.h
@@ -96,6 +96,12 @@ public:
 	 */
 	void OfferMissions(Entity* entity, uint32_t specifiedMissionId = 0);
 
+	/**
+	 * Returns whether this entity offers or accepts a mission, on its own or as one of a random mission's pool
+	 * @param missionId the mission to look for
+	 */
+	bool HasMission(uint32_t missionId) const;
+
 	// RequestLinkedMission after a mission window: offers the next mission of this giver, if there is a new one
 	void OfferLinkedMission(Entity* entity, uint32_t missionID);
 
diff --git a/dGame/dGameMessages/MissionMessages.cpp b/dGame/dGameMessages/MissionMessages.cpp
index 23d047929..26aeeb4e0 100644
--- a/dGame/dGameMessages/MissionMessages.cpp
+++ b/dGame/dGameMessages/MissionMessages.cpp
@@ -143,13 +143,12 @@ namespace GameMessages {
 	void MissionDialogueOK::Handle(Entity& entityRef, const SystemAddress& sysAddr) {
 		Entity* entity = &entityRef;
 		Entity* player = Game::entityManager->GetEntity(responder);
-		if (!player) {
-			LOG("MissionDialogueOK for mission %i from unknown responder %llu", missionID, responder);
+		// A player answers a mission dialogue for themselves
+		if (!player || !player->IsPlayer() || player->GetSystemAddress() != sysAddr) {
+			LOG("Responder %llu of MissionDialogueOK for mission %i is not the player that sent it", responder, missionID);
 			return;
 		}
 
-		entity->GetScript()->OnMissionDialogueOK(entity, player, missionID, iMissionState);
-
 		// Get the player's mission component
 		MissionComponent* missionComponent = static_cast<MissionComponent*>(player->GetComponent(eReplicaComponentType::MISSION));
 		if (!missionComponent) {
@@ -157,9 +156,35 @@ namespace GameMessages {
 			return;
 		}
 
-		if (iMissionState == eMissionState::AVAILABLE || iMissionState == eMissionState::COMPLETE_AVAILABLE) {
+		// The mission has to be one the object the dialogue belongs to gives or takes
+		const auto* const missionOfferComponent = entity->GetComponent<MissionOfferComponent>();
+		if (!missionOfferComponent || !missionOfferComponent->HasMission(missionID)) {
+			LOG("Object %llu (LOT %i) has no mission %i for player %llu to answer", entity->GetObjectID(), entity->GetLOT(), missionID, player->GetObjectID());
+			return;
+		}
+
+		const bool isAccepting = iMissionState == eMissionState::AVAILABLE || iMissionState == eMissionState::COMPLETE_AVAILABLE;
+		const bool isCompleting = iMissionState == eMissionState::READY_TO_COMPLETE || iMissionState == eMissionState::COMPLETE_READY_TO_COMPLETE;
+
+		if (isAccepting && !missionComponent->CanAccept(missionID)) {
+			LOG("Player %llu tried to accept mission %i, which they can not accept", player->GetObjectID(), missionID);
+			return;
+		}
+
+		if (isCompleting) {
+			// Only a mission with all of its tasks done can be handed in
+			const auto* const readyMission = missionComponent->GetMission(missionID);
+			if (!readyMission || !readyMission->IsReadyToComplete()) {
+				LOG("Player %llu tried to hand in mission %i, which is not ready to complete", player->GetObjectID(), missionID);
+				return;
+			}
+		}
+
+		entity->GetScript()->OnMissionDialogueOK(entity, player, missionID, iMissionState);
+
+		if (isAccepting) {
 			missionComponent->AcceptMission(missionID);
-		} else if (iMissionState == eMissionState::READY_TO_COMPLETE || iMissionState == eMissionState::COMPLETE_READY_TO_COMPLETE) {
+		} else if (isCompleting) {
 			// LWOMissionComponent::MissionWindowOK (0x00d501f0) only turns a mission in when every reward fits
 			// (CanReceiveAllRewards, with the reward the player picked)
 			const auto* const mission = missionComponent->GetMission(missionID);