Extended rework & ramping event scheduler (#11362)

Content.Server/StationEvents/Events/StationEventSystem.cs

@@ -179,6 +179,26 @@ namespace Content.Server.StationEvents.Events
                 .Where(p => p.Configuration is StationEventRuleConfiguration).ToArray());
         }
 
+        public float GetSeverityModifier()
+        {
+            var ev = new GetSeverityModifierEvent();
+            RaiseLocalEvent(ev);
+            return ev.Modifier;
+        }
+
         #endregion
     }
+
+    /// <summary>
+    ///     Raised broadcast to determine what the severity modifier should be for an event, some positive number that can be multiplied with various things.
+    ///     Handled by usually other game rules (like the ramping scheduler).
+    ///     Most events should try and make use of this if possible.
+    /// </summary>
+    public sealed class GetSeverityModifierEvent : EntityEventArgs
+    {
+        /// <summary>
+        ///     Should be multiplied/added to rather than set, for commutativity.
+        /// </summary>
+        public float Modifier = 1.0f;
+    }
 }