dropped requirements for base in skill.json

config/schemas/skill.json

@@ -26,11 +26,13 @@
             }
         },
 
-        "required" : ["base", "basic", "advanced", "expert"],
+        "required" : ["basic", "advanced", "expert"],
 
         "properties": {
             "base":{
-                "$ref" : "#/definitions/skillBonus"
+                "type": "object",
+                "description": "will be merged with all levels",
+                "additionalProperties": true
             },
             "basic":{
                 "$ref" : "#/definitions/skillBonus"