First Examples: Added FireBurn effect,

.editorconfig

@@ -1,5 +1,6 @@
 # EditorConfig for .NET template
 root = true
+
 [*]
 end_of_line = lf
 insert_final_newline = true

EoM_Redux/D20/Effects/FireBurn.cs

@@ -0,0 +1,19 @@
+namespace EoM_Redux;
+
+public class FireBurn : IOvertEffect
+{
+    public FireBurn(int damage = 0, int duration = 3)
+    {
+        Damage = damage;
+        Duration = duration;
+    }
+
+    public string Name { get; } = "Burning";
+    public int Damage { get; }
+    public int Duration { get; }
+
+    public void ApplyEffect()
+    {
+        throw new NotImplementedException();
+    }
+}

EoM_Redux/D20/Elements/Fire.cs

@@ -2,10 +2,13 @@ namespace EoM_Redux;
 
 public class Fire : IElement
 {
-    public int Damage { get; set; }
-
     public Fire(int damage)
     {
         Damage = damage;
     }
+
+    public int Damage { get; set; }
+
+    public List<ISubtleEffect> ISubtleEffects { get; }
+    public List<IOvertEffect> IOvertEffects { get; }
 }

EoM_Redux/D20/Spells/FireBall.cs

@@ -2,5 +2,7 @@
 
 public class FireBall : ISpell
 {
+    public IOvertEffect OvertEffect => new FireBurn(10);
     public SpellType Type => SpellType.Overt;
+    public IElement Element => new Fire(10);
 }

EoM_Redux/IElement.cs

@@ -2,4 +2,6 @@ namespace EoM_Redux;
 
 public interface IElement
 {
+    List<ISubtleEffect> ISubtleEffects { get; }
+    List<IOvertEffect> IOvertEffects { get; }
 }

EoM_Redux/ISpell.cs

@@ -3,4 +3,5 @@ namespace EoM_Redux;
 public interface ISpell
 {
     public SpellType Type { get; }
+    public IElement Element { get; }
 }