diff --git a/src/game/engine/anim.cpp b/src/game/engine/anim.cpp
index 67366f27..0d45b825 100644
--- a/src/game/engine/anim.cpp
+++ b/src/game/engine/anim.cpp
@@ -56,9 +56,9 @@ AnimClass::AnimClass(AnimType type, coord_t coord, unsigned char loop_delay, uns
         m_Class->Set_End(m_Class->Get_End());
     }
     if (m_Class->Is_Normalized()) {
-        m_LoopStage.Set_Delay(g_Options.Normalize_Delay(m_Class->Get_Rate()));
+        m_LoopStage.Set_Rate(g_Options.Normalize_Delay(m_Class->Get_Rate()));
     } else {
-        m_LoopStage.Set_Delay(m_Class->Get_Rate());
+        m_LoopStage.Set_Rate(m_Class->Get_Rate());
     }
     m_LoopStage.Set_Stage(0);
     if (m_Class->Is_Surface()) {
diff --git a/src/game/engine/door.cpp b/src/game/engine/door.cpp
index 0c0b9c24..29eaab97 100644
--- a/src/game/engine/door.cpp
+++ b/src/game/engine/door.cpp
@@ -20,9 +20,9 @@
  */
 void DoorClass::AI()
 {
-    if (m_DoorTimer.Stage_Changed()) {
+    if (m_DoorTimer.Stage_AI()) {
         if (m_DoorTimer.Get_Stage() >= m_Stage) {
-            m_DoorTimer.Set_Delay(0);
+            m_DoorTimer.Set_Rate(0);
 
             switch (m_State) {
                 case DOOR_OPENING:
@@ -41,9 +41,9 @@ void DoorClass::AI()
 }
 
 /**
- * @brief Sets the door opening process to take the given stages with the given frame delay between each stage.
+ * @brief Sets the door opening process to take the given stages with the given rate between each stage.
  */
-BOOL DoorClass::Open_Door(int delay, int stages)
+BOOL DoorClass::Open_Door(int rate, int stages)
 {
     if (m_State != DOOR_CLOSED && m_State != DOOR_CLOSING) {
         return false;
@@ -52,15 +52,15 @@ BOOL DoorClass::Open_Door(int delay, int stages)
     m_State = DOOR_OPENING;
     m_Stage = stages - 1;
     m_DoorTimer.Set_Stage(0);
-    m_DoorTimer.Set_Delay(delay);
+    m_DoorTimer.Set_Rate(rate);
 
     return true;
 }
 
 /**
- * @brief Sets the door closing process to take the given stages with the given frame delay between each stage.
+ * @brief Sets the door closing process to take the given stages with the given rate between each stage.
  */
-BOOL DoorClass::Close_Door(int delay, int stages)
+BOOL DoorClass::Close_Door(int rate, int stages)
 {
     if (m_State != DOOR_OPEN && m_State != DOOR_OPENING) {
         return false;
@@ -69,7 +69,7 @@ BOOL DoorClass::Close_Door(int delay, int stages)
     m_State = DOOR_CLOSING;
     m_Stage = stages - 1;
     m_DoorTimer.Set_Stage(0);
-    m_DoorTimer.Set_Delay(delay);
+    m_DoorTimer.Set_Rate(rate);
 
     return true;
 }
diff --git a/src/game/engine/door.h b/src/game/engine/door.h
index 98030473..6cc3c9d2 100644
--- a/src/game/engine/door.h
+++ b/src/game/engine/door.h
@@ -37,8 +37,8 @@ class DoorClass
     DoorClass(const NoInitClass &noinit) : m_DoorTimer(noinit) {}
 
     void AI();
-    BOOL Open_Door(int delay, int stages);
-    BOOL Close_Door(int delay, int stages);
+    BOOL Open_Door(int rate, int stages);
+    BOOL Close_Door(int rate, int stages);
     int Door_Stage() const;
     void Mark_To_Redraw() const { m_ToRedraw = true; }
     BOOL To_Redraw() const { return m_ToRedraw; }
diff --git a/src/game/engine/factory.cpp b/src/game/engine/factory.cpp
index 4ff30aa1..898805f4 100644
--- a/src/game/engine/factory.cpp
+++ b/src/game/engine/factory.cpp
@@ -79,7 +79,7 @@ void FactoryClass::AI()
 {
     if (!m_IsSuspended && (m_Object != nullptr || m_SpecialItem != -1)) {
         if (!Has_Completed()) {
-            if (m_ProductionTime.Stage_Changed()) {
+            if (m_ProductionTime.Stage_AI()) {
                 m_IsDifferent = true;
                 unsigned int tick_cost = std::min(Cost_Per_Tick(), m_Balance);
                 if (m_Owner->Available_Money() >= tick_cost) {
@@ -95,7 +95,7 @@ void FactoryClass::AI()
             #endif
                 if (m_ProductionTime.Get_Stage() == MAX_CLOCK_STAGES) {
                     m_IsSuspended = true;
-                    m_ProductionTime.Set_Delay(0);
+                    m_ProductionTime.Set_Rate(0);
                     m_Owner->Spend_Money(m_Balance);
                     m_Balance = 0;
                 }
@@ -123,7 +123,7 @@ BOOL FactoryClass::Set(TechnoTypeClass &objecttype, HouseClass &house)
     m_IsSuspended = true;
 
     m_ProductionTime.Set_Stage(0);
-    m_ProductionTime.Set_Delay(0);
+    m_ProductionTime.Set_Rate(0);
 
     m_Balance = 0;
 
@@ -161,7 +161,7 @@ BOOL FactoryClass::Set(int &special, HouseClass &house)
     m_Balance = 0;
 
     m_ProductionTime.Set_Stage(0);
-    m_ProductionTime.Set_Delay(0);
+    m_ProductionTime.Set_Rate(0);
 
     return m_SpecialItem != -1;
 }
@@ -178,14 +178,14 @@ void FactoryClass::Set(TechnoClass &object)
     m_Balance = 0;
 
     m_ProductionTime.Set_Stage(0);
-    m_ProductionTime.Set_Delay(0);
+    m_ProductionTime.Set_Rate(0);
 }
 
 BOOL FactoryClass::Suspend()
 {
     if (!m_IsSuspended) {
         m_IsSuspended = true;
-        m_ProductionTime.Set_Delay(0);
+        m_ProductionTime.Set_Rate(0);
         return true;
     }
     return false;
@@ -216,7 +216,7 @@ BOOL FactoryClass::Abandon()
         m_IsDifferent = true;
 
         m_ProductionTime.Set_Stage(0);
-        m_ProductionTime.Set_Delay(0);
+        m_ProductionTime.Set_Rate(0);
 
         ++g_ScenarioInit;
 
@@ -264,7 +264,7 @@ BOOL FactoryClass::Completed()
         m_IsSuspended = true;
         m_IsDifferent = true;
         m_ProductionTime.Set_Stage(0);
-        m_ProductionTime.Set_Delay(0);
+        m_ProductionTime.Set_Rate(0);
         return true;
     }
     if (m_SpecialItem != -1 && m_ProductionTime.Get_Stage() == MAX_CLOCK_STAGES) {
@@ -272,7 +272,7 @@ BOOL FactoryClass::Completed()
         m_IsSuspended = true;
         m_IsDifferent = true;
         m_ProductionTime.Set_Stage(0);
-        m_ProductionTime.Set_Delay(0);
+        m_ProductionTime.Set_Rate(0);
         return true;
     }
     return false;
diff --git a/src/game/engine/factory.h b/src/game/engine/factory.h
index 7c557576..2dcd9615 100644
--- a/src/game/engine/factory.h
+++ b/src/game/engine/factory.h
@@ -61,7 +61,7 @@ class FactoryClass
     BOOL Abandon();
     int Completion() const { return m_ProductionTime.Get_Stage(); }
     BOOL Has_Completed() const;
-    BOOL Is_Building() const { return m_ProductionTime.Get_Delay() != 0; }
+    BOOL Is_Building() const { return m_ProductionTime.Get_Rate() != 0; }
     TechnoClass *const Get_Object() const { return m_Object; }
     int Get_Special_Item() const { return m_SpecialItem; }
     unsigned int Cost_Per_Tick() const;
diff --git a/src/game/engine/stage.h b/src/game/engine/stage.h
index 038ae170..50e27c13 100644
--- a/src/game/engine/stage.h
+++ b/src/game/engine/stage.h
@@ -24,40 +24,50 @@
 class StageClass
 {
 public:
-    StageClass() : m_Stage(0), m_Timer(0), m_Delay(0) {}
+    StageClass() : m_Stage(0), m_Timer(0), m_Rate(0) {}
     StageClass(const NoInitClass &noinit) : m_Timer(noinit) {}
     StageClass &operator=(StageClass &that);
 
     int Get_Stage() const { return m_Stage; }
     void Set_Stage(int stage) { m_Stage = stage; }
-    int Get_Delay() const { return m_Delay; }
-    void Set_Delay(int delay);
-    BOOL Stage_Changed();
+    int Get_Rate() const { return m_Rate; }
+    void Set_Rate(int rate);
+    BOOL To_Change();
+    BOOL Stage_AI();
     void Reset();
 
 private:
     int m_Stage; // Current stage we are at.
     TCountDownTimerClass<FrameTimerClass> m_Timer; // Countdown timer, 0 indicates time to go to next stage.
-    int m_Delay; // Delay in frames to the next stage transition.
+    int m_Rate; // Rate at which the stage transition occurs.
 };
 
 /**
  * @brief Sets the delay between stage transitions in game frames.
  */
-inline void StageClass::Set_Delay(int delay)
+inline void StageClass::Set_Rate(int rate)
 {
-    m_Timer = delay;
-    m_Delay = delay;
+    m_Timer = rate;
+    m_Rate = rate;
 }
 
 /**
- * @brief Checks if a stage change has occured.
+ * @brief Is a stage change going to occur.
  */
-inline BOOL StageClass::Stage_Changed()
+inline BOOL StageClass::To_Change()
 {
-    if (m_Timer.Time() <= 0 && m_Delay > 0) {
+    return m_Timer.Expired() && m_Rate > 0;
+}
+
+/**
+ * @brief Handles a stage change should it be needed.
+ * Returns if a stage change has occured.
+ */
+inline BOOL StageClass::Stage_AI()
+{
+    if (To_Change()) {
         ++m_Stage;
-        m_Timer = m_Delay;
+        m_Timer = m_Rate;
 
         return true;
     }
@@ -72,7 +82,7 @@ inline void StageClass::Reset()
 {
     m_Stage = 0;
     m_Timer = 0;
-    m_Delay = 0;
+    m_Rate = 0;
 }
 
 inline StageClass &StageClass::operator=(StageClass &that)
@@ -80,7 +90,7 @@ inline StageClass &StageClass::operator=(StageClass &that)
     if (this != &that) {
         m_Stage = that.m_Stage;
         m_Timer = that.m_Timer;
-        m_Delay = that.m_Delay;
+        m_Rate = that.m_Rate;
     }
 
     return *this;
diff --git a/src/game/engine/techno.cpp b/src/game/engine/techno.cpp
index 2f097f8d..ad71cb13 100644
--- a/src/game/engine/techno.cpp
+++ b/src/game/engine/techno.cpp
@@ -1157,7 +1157,7 @@ void TechnoClass::Do_Uncloak()
 
             m_CloakState = CLOAK_UNCLOAKING;
             m_CloakingStage.Set_Stage(0);
-            m_CloakingStage.Set_Delay(1);
+            m_CloakingStage.Set_Rate(1);
 
             // BUGFIX: The following stops the uncloaking sound from playing upon game start.
             if (g_GameFrame > 25) {
@@ -1183,7 +1183,7 @@ void TechnoClass::Do_Cloak()
 
             m_CloakState = CLOAK_CLOAKING;
             m_CloakingStage.Set_Stage(0);
-            m_CloakingStage.Set_Delay(1);
+            m_CloakingStage.Set_Rate(1);
 
             // BUGFIX: The following stops the cloaking sound from playing upon game start.
             if (g_GameFrame > 25) {
diff --git a/src/game/engine/terrain.cpp b/src/game/engine/terrain.cpp
index f35e6d0c..33bb795d 100644
--- a/src/game/engine/terrain.cpp
+++ b/src/game/engine/terrain.cpp
@@ -44,7 +44,7 @@ TerrainClass::TerrainClass(TerrainType type, cell_t cellnum) :
             delete this;
         }
     }
-    m_AnimStage.Set_Delay(0);
+    m_AnimStage.Set_Rate(0);
 }
 
 /**
@@ -144,7 +144,7 @@ void TerrainClass::AI()
     if (What_Type() == TERRAIN_MINE && !(g_GameFrame % (900 * g_Rule.Ore_Growth_Rate()))) {
         g_Map[As_Cell(As_Target())].Spread_Ore(true);
     }
-    if (m_AnimStage.Stage_Changed()) {
+    if (m_AnimStage.Stage_AI()) {
         Mark(MARK_REMOVE);
         if (m_Crumbling) {
             if (m_AnimStage.Get_Stage() == Get_Build_Frame_Count(Get_Image_Data()) - 1) {
@@ -331,7 +331,7 @@ void TerrainClass::Start_To_Crumble()
     if (!m_Crumbling) {
         m_Crumbling = true;
         m_AnimStage.Set_Stage(0);
-        m_AnimStage.Set_Delay(2);
+        m_AnimStage.Set_Rate(2);
     }
 }
 
diff --git a/src/game/engine/unit.cpp b/src/game/engine/unit.cpp
index 51d83e5d..e215a51a 100644
--- a/src/game/engine/unit.cpp
+++ b/src/game/engine/unit.cpp
@@ -50,7 +50,7 @@ UnitClass::UnitClass(UnitType type, HousesType house) :
     m_Cloakable = Class_Of().Is_Cloakable();
 
     if (Class_Of().Is_Viceroid()) {
-         m_AnimStage.Set_Delay(g_Options.Normalize_Delay(3));
+         m_AnimStage.Set_Rate(g_Options.Normalize_Delay(3));
     }
 
     m_Bit2_16 = !Class_Of().Is_Two_Shooter();