diff --git a/include/game_state.h b/include/game_state.h
index b9ee2a5..eba388d 100644
--- a/include/game_state.h
+++ b/include/game_state.h
@@ -382,6 +382,8 @@ private:
     void incr_turn();
     void decr_turn();
 
+    void check_draw_pile_integrity() const;
+
     static constexpr uint8_t no_endgame = std::numeric_limits<uint8_t>::max();
     static constexpr player_t draw_pile = num_players;
     static constexpr player_t trash_or_play_stack = num_players + 1;
diff --git a/include/game_state.hpp b/include/game_state.hpp
index 9dbded4..b939d6c 100644
--- a/include/game_state.hpp
+++ b/include/game_state.hpp
@@ -1,4 +1,5 @@
 #include <algorithm>
+#include <iostream>
 
 #include "myassert.h"
 #include "game_state.h"
@@ -164,6 +165,26 @@ namespace Hanabi {
         }
     }
 
+    template<suit_t num_suits, player_t num_players, hand_index_t hand_size>
+    void HanabiState<num_suits, num_players, hand_size>::check_draw_pile_integrity() const
+    {
+      if (not _relative_representation.initialized)
+      {
+        return;
+      }
+      if (_draw_pile.size() >= 2) {
+        auto copy = _draw_pile;
+        copy.sort([](CardMultiplicity const & card1, CardMultiplicity const & card2){
+          return card1.card.rank < card2.card.rank or (card1.card.rank == card2.card.rank and card1.card.suit < card2.card.suit);
+        });
+        auto before = copy.begin();
+        for(auto it = std::next(copy.begin()); it != copy.end(); ++it) {
+          ASSERT(before->card != it->card);
+          ++before;
+        }
+      }
+    }
+
     template<suit_t num_suits, player_t num_players, hand_index_t hand_size>
     bool HanabiState<num_suits, num_players, hand_size>::is_playable(const Hanabi::Card &card) const {
         return card.rank == _stacks[card.suit] - 1;
@@ -186,6 +207,7 @@ namespace Hanabi {
 
     template<suit_t num_suits, player_t num_players, hand_index_t hand_size>
     unsigned long HanabiState<num_suits, num_players, hand_size>::play_and_potentially_update(hand_index_t index) {
+        check_draw_pile_integrity();
         ASSERT(index < _hands[_turn].size());
         const Card played_card = _hands[_turn][index];
         if (!is_playable(played_card)) {
@@ -208,6 +230,7 @@ namespace Hanabi {
         const unsigned long multiplicity = draw(index);
 
         incr_turn();
+        check_draw_pile_integrity();
         return multiplicity;
     }
 
@@ -218,6 +241,7 @@ namespace Hanabi {
 
     template<suit_t num_suits, player_t num_players, hand_index_t hand_size>
     unsigned long HanabiState<num_suits, num_players, hand_size>::discard_and_potentially_update(hand_index_t index) {
+        check_draw_pile_integrity();
         ASSERT(index < _hands[_turn].size());
         ASSERT(_num_clues != max_num_clues);
 
@@ -229,6 +253,7 @@ namespace Hanabi {
         _actions_log.emplace(ActionType::discard, discarded_card, index);
 
         incr_turn();
+        check_draw_pile_integrity();
         return multiplicity;
     }
 
@@ -449,6 +474,7 @@ namespace Hanabi {
     template<suit_t num_suits, player_t num_players, hand_index_t hand_size>
     void
     HanabiState<num_suits, num_players, hand_size>::revert_play() {
+      check_draw_pile_integrity();
         const BacktrackAction last_action = _actions_log.top();
         _actions_log.pop();
         ASSERT(last_action.action_type == ActionType::play);
@@ -463,10 +489,12 @@ namespace Hanabi {
             _stacks[last_action.discarded.suit]++;
         }
         _score--;
+      check_draw_pile_integrity();
     }
 
     template<suit_t num_suits, player_t num_players, hand_index_t hand_size>
     void HanabiState<num_suits, num_players, hand_size>::revert_discard() {
+      check_draw_pile_integrity();
         const BacktrackAction last_action = _actions_log.top();
         _actions_log.pop();
 
@@ -479,6 +507,7 @@ namespace Hanabi {
         _pace++;
 
         revert_draw(last_action.index, last_action.discarded);
+      check_draw_pile_integrity();
     }
 
     template<suit_t num_suits, player_t num_players, hand_index_t hand_size>
@@ -793,6 +822,7 @@ namespace Hanabi {
             revert_action();
         } else {
             unsigned sum_of_multiplicities = 0;
+            [[maybe_unused]] const auto pile = _draw_pile;
             for(size_t i = 0; i < _draw_pile.size(); i++) {
                 const unsigned long multiplicity = do_action();
                 sum_of_multiplicities += multiplicity;