diff --git a/game/model/hero.scm b/game/model/hero.scm
index 1fee556..2d49f16 100644
--- a/game/model/hero.scm
+++ b/game/model/hero.scm
@@ -8,21 +8,21 @@
   #:use-module (chickadee math vector)
   #:use-module (game util pipe)
   #:use-module (game model level)
+  #:use-module (game model runner)
   #:export (hero-load
             hero-state 
             hero-bloat
-            hero-position hero-with-position
-            hero-x hero-with-x
-            hero-y hero-with-y
+            hero-position
+            hero-x 
+            hero-y
             hero-update
             ))
 
 
 (define-immutable-record-type <hero>
-  (%make-hero position state bloat)
+  (%make-hero runner bloat)
   hero?
-  (position hero-position hero-with-position)
-  (state hero-state hero-with-state)                    ;; 'go-left 'go-right 'climb 'fall 'stationary
+  (runner hero-runner hero-with-runner)
   (bloat hero-bloat hero-with-bloat)                    ;; 0.0 to 2.0, how much the hero is inflated
   )
 
@@ -30,75 +30,30 @@
 (define default-bloat 1.0)
 
 (define (hero-load level)
-  (let ((initial-position (level-find-hero level)))
-    (%make-hero initial-position default-state default-bloat)))
+  "Create a hero at the position in the level map"
+  (let ((runner (runner-load (level-find-hero level))))
+    (%make-hero runner default-bloat)))
 
 (define (hero-x hero)
   "return the x coordinate as an integer"
-  (inexact->exact (floor (vec2-x (hero-position hero)))))
+  (runner-x (hero-runner hero)))
 
 (define (hero-y hero)
   "return the y coordinate as an integer"
-  (inexact->exact (floor (vec2-y (hero-position hero)))))
+  (runner-y (hero-runner hero))
+  )
 
-(define (hero-with-x hero x)
-  (hero-with-position hero (vec2 x (hero-y hero))))
+(define (hero-state hero)
+  "return the current state of the hero"
+  (runner-state (hero-runner hero)))
 
-(define (hero-with-y hero y)
-  (hero-with-position hero (vec2 (hero-x hero) y)))
+(define (hero-position hero)
+  "return the current position of the hero"
+  (runner-position (hero-runner hero)))
 
 
-;; return next state of hero 
-;; @returns 'go-left 'go-right 'climb 'fall 'stationary
-(define (next-state hero level inputs)
-  (let* ((position (hero-position hero))
-         (state (hero-state hero))
-         (tile-below (level-tile-at level (vec2 (hero-x hero) (1- (hero-y hero))))))
-    (cond
-     ((equal? (level-tile-at level position) 'ladder) 'climb)
-     ((> (floor-remainder (hero-y hero) level-cell-size) 0) 'fall)
-     ((equal? tile-below 'empty) 'fall)
-     (else (cond
-            ((member 'left inputs) 'go-left)
-            ((member 'right inputs) 'go-right)
-            (else 'stationary))))))
-
-(define (input->movement input distance)
-  (case input
-    ((left) (vec2 (- distance) 0))
-    ((right) (vec2 distance 0))
-    ((up) (vec2 0 distance))
-    ((down) (vec2 0 (- distance)))
-    (else (vec2 0 0))))
-
-
-(define (next-position position state inputs distance)
-  (case state
-    ((fall) (vec2- position (vec2 0 distance)))
-    ((go-left) (vec2- position (vec2 distance 0)))
-    ((go-right) (vec2+ position (vec2 distance 0)))
-    ((stationary) position)
-    ((climb) (fold (lambda (input movement)
-                     (vec2+ movement (input->movement input distance)))
-                   position
-                   inputs))
-    (else position)
-    ))
-
-(define speed 50.0)
-
 (define (hero-update hero level inputs dt)
-  (let* ((state (next-state hero level inputs))
-         (distance (* dt speed))
-         (position (next-position (hero-position hero) (hero-state hero) inputs distance))
-         (tile (level-tile-at level position))
-         )
-    (hero-with-state 
-     (if (member tile '(empty ladder other))
-         (hero-with-position hero position)
-         (hero-with-position hero (vec2 (hero-x hero) (hero-y hero))) ;; round position
-         )
-     state)))
+  (hero-with-runner hero (runner-update (hero-runner hero) level inputs dt)))
 
 
 
@@ -109,57 +64,10 @@
        (hero (hero-load level))
        (default-position (level-find-hero level)))
   (test-assert (hero? hero))
-  (test-equal default-position (hero-position hero))
-  (test-equal default-state (hero-state hero))
   (test-equal default-bloat (hero-bloat hero))
   
-  (test-equal (vec2 10 20)  (hero-position (hero-with-position hero (vec2 10 20))))
-  (test-equal default-position (hero-position hero))
-  (test-equal 'go-left (hero-state (hero-with-state hero 'go-left)))
-  (test-equal default-state (hero-state hero))
   (test-equal 1.5 (hero-bloat (hero-with-bloat hero 1.5)))
   (test-equal default-bloat (hero-bloat hero))
   
-  (test-equal 16 (hero-x (hero-with-position hero (vec2 16.34 20.78))))
-  (test-equal 20 (hero-y (hero-with-position hero (vec2 16.34 20.78))))
-  
-  (test-equal 'fall (next-state hero level '()))
-  (let ((hero (hero-with-position hero (vec2 16 16))))
-    (test-equal 'stationary (next-state hero level '()))
-    (test-equal 'go-left (next-state hero level '(left)))
-    (test-equal 'go-right (next-state hero level '(right))))
-  (let ((hero (hero-with-position hero (vec2 48 32))))
-    (test-equal 'stationary (next-state hero level '())))
-  (let ((hero (hero-with-position hero (vec2 48 31))))
-    (test-equal 'climb (next-state hero level '())))
-  (let ((hero (hero-with-position hero (vec2 32 31))))
-    (test-equal 'fall (next-state hero level '())))
-  
-  (test-equal (vec2 32.0 31.0) (next-position (vec2 32.0 32.0) 'fall '() 1.0))
-  
-  (test-equal (vec2 31.0 32.0) (next-position (vec2 32.0 32.0) 'go-left '() 1.0))
-  (test-equal (vec2 33.0 32.0) (next-position (vec2 32.0 32.0) 'go-right '() 1.0))
-  (test-equal (vec2 32.0 32.0) (next-position (vec2 32.0 32.0) 'stationary '() 1.0))
-  
-  
-  (test-equal (vec2 31.0 32.0) (next-position (vec2 32.0 32.0) 'climb '(left) 1.0))
-  (test-equal (vec2 33.0 32.0) (next-position (vec2 32.0 32.0) 'climb '(right) 1.0))
-  (test-equal (vec2 32.0 31.0) (next-position (vec2 32.0 32.0) 'climb '(down) 1.0))
-  (test-equal (vec2 32.0 33.0) (next-position (vec2 32.0 32.0) 'climb '(up) 1.0))
-  
-  
-  (test-equal 
-      (vec2 32.0 16.0) 
-    (hero-position
-     (hero-update
-      (hero-with-state 
-       (hero-with-position hero (vec2 32 16.3)) 
-       'fall)
-      level
-      '()
-      0.017
-      )
-     ))
-  )
+  (test-end "hero-model"))
 
-(test-end "hero-model")
diff --git a/game/model/runner.scm b/game/model/runner.scm
index 49f06b3..f2a3828 100644
--- a/game/model/runner.scm
+++ b/game/model/runner.scm
@@ -47,6 +47,7 @@
 ;; return next state of runner 
 ;; @returns 'go-left 'go-right 'climb 'fall 'stationary
 (define (next-state runner level inputs)
+  "return the next state of the runner based on the current state, level and inputs"
   (let* ((position (runner-position runner))
          (state (runner-state runner))
          (tile-below (level-tile-at level (vec2 (runner-x runner) (1- (runner-y runner))))))