Scoping rules in Clojure

Even though I have used Clojure, I hadn't looked at the scoping rules in detail. I am getting more confused as I read the documentations. I made a small test to try out the scoping resolutions and am apalled at the complexity. Could somebody explain the intent and various rules that Clojure uses?

(def x 1)

(defn dummy-fn2[]
    (+ x 1))        

(defn dummy-fn[]
    (println "entering function: " x)
      (let [x 100]
         (println "after let: " x)
         (let [x (dummy-fn2)]
            (println "after let and dummy2: " x)
            (binding [x 100]
             (println "after binding: " x)
             (let [x (dummy-fn2)]
               (println "after binding and dummy2: " x))))))

1:2 foo=> (dummy-fn)
entering function:  1
after let:  100
after let and dummy2:  2
after binding:  2
after binding and dummy2:  101
nil