diff --git a/src/games/game.h b/src/games/game.h
index d9d567585..5b0fc8fbb 100644
--- a/src/games/game.h
+++ b/src/games/game.h
@@ -184,10 +184,10 @@ class GameInfosetRep : public GameObject {
   int m_number;
   std::string m_label;
   GamePlayerRep *m_player;
-  Array<GameActionRep *> m_actions;
+  std::vector<GameActionRep *> m_actions;
   std::vector<GameNodeRep *> m_members;
   int flag{0}, whichbranch{0};
-  Array<Number> m_probs;
+  std::vector<Number> m_probs;
 
   GameInfosetRep(GameRep *p_efg, int p_number, GamePlayerRep *p_player, int p_actions);
   ~GameInfosetRep() override;
@@ -214,7 +214,7 @@ class GameInfosetRep : public GameObject {
   /// Returns the number of actions available at the information set
   size_t NumActions() const { return m_actions.size(); }
   /// Returns the p_index'th action at the information set
-  GameAction GetAction(int p_index) const { return m_actions[p_index]; }
+  GameAction GetAction(int p_index) const { return m_actions.at(p_index - 1); }
   /// Returns the actions available at the information set
   Array<GameAction> GetActions() const;
   //@}
@@ -230,7 +230,7 @@ class GameInfosetRep : public GameObject {
     if (p_action->GetInfoset() != GameInfoset(const_cast<GameInfosetRep *>(this))) {
       throw MismatchException();
     }
-    return m_probs[p_action->GetNumber()];
+    return m_probs.at(p_action->GetNumber() - 1);
   }
 };
 
diff --git a/src/games/gametree.cc b/src/games/gametree.cc
index 4cc8f2764..711195609 100644
--- a/src/games/gametree.cc
+++ b/src/games/gametree.cc
@@ -124,23 +124,22 @@ void GameTreeRep::DeleteAction(GameAction p_action)
   }
 
   IncrementVersion();
-  size_t where;
-  for (where = 1; where <= infoset->m_actions.size() && infoset->m_actions[where] != action;
-       where++)
-    ;
-  infoset->m_actions[where]->Invalidate();
-  erase_atindex(infoset->m_actions, where);
+  auto where = std::find(infoset->m_actions.begin(), infoset->m_actions.end(), action);
+  auto offset = where - infoset->m_actions.begin();
+  (*where)->Invalidate();
+  infoset->m_actions.erase(where);
   if (infoset->m_player->IsChance()) {
-    erase_atindex(infoset->m_probs, where);
+    infoset->m_probs.erase(std::next(infoset->m_probs.begin(), offset));
     NormalizeChanceProbs(infoset);
   }
   infoset->RenumberActions();
 
   for (auto member : infoset->m_members) {
-    DeleteTree(member->m_children[where - 1]);
+    auto it = std::next(member->m_children.begin(), offset);
+    DeleteTree(*it);
     m_numNodes--;
-    member->m_children[where - 1]->Invalidate();
-    member->m_children.erase(std::next(member->m_children.begin(), where - 1));
+    (*it)->Invalidate();
+    member->m_children.erase(it);
   }
   ClearComputedValues();
   Canonicalize();
@@ -159,7 +158,7 @@ GameInfosetRep::GameInfosetRep(GameRep *p_efg, int p_number, GamePlayerRep *p_pl
   std::generate(m_actions.begin(), m_actions.end(),
                 [this, i = 1]() mutable { return new GameActionRep(i++, "", this); });
   if (p_player->IsChance()) {
-    m_probs = Array<Number>(m_actions.size());
+    m_probs = std::vector<Number>(m_actions.size());
     std::fill(m_probs.begin(), m_probs.end(), Rational(1, m_actions.size()));
   }
   m_player->m_infosets.push_back(this);
@@ -224,20 +223,17 @@ GameAction GameTreeRep::InsertAction(GameInfoset p_infoset, GameAction p_action
   }
 
   IncrementVersion();
-  int where = p_infoset->m_actions.size() + 1;
-  if (p_action) {
-    for (where = 1; p_infoset->m_actions[where] != p_action; where++)
-      ;
-  }
+  auto where = std::find(p_infoset->m_actions.begin(), p_infoset->m_actions.end(), p_action);
+  auto offset = where - p_infoset->m_actions.begin();
 
-  auto *action = new GameActionRep(where, "", p_infoset);
-  p_infoset->m_actions.insert(std::next(p_infoset->m_actions.cbegin(), where - 1), action);
+  auto *action = new GameActionRep(offset + 1, "", p_infoset);
+  p_infoset->m_actions.insert(where, action);
   if (p_infoset->m_player->IsChance()) {
-    p_infoset->m_probs.insert(std::next(p_infoset->m_probs.cbegin(), where - 1), Number());
+    p_infoset->m_probs.insert(std::next(p_infoset->m_probs.cbegin(), offset), Number());
   }
   p_infoset->RenumberActions();
   for (const auto &member : p_infoset->m_members) {
-    member->m_children.insert(std::next(member->m_children.cbegin(), where - 1),
+    member->m_children.insert(std::next(member->m_children.cbegin(), offset),
                               new GameNodeRep(this, member));
   }