diff --git a/src/robotwar/constants.clj b/src/robotwar/constants.clj
index 0b4458a..eed7a20 100644
--- a/src/robotwar/constants.clj
+++ b/src/robotwar/constants.clj
@@ -4,4 +4,7 @@
 (def MAX-ACCEL 4.0)
 (def ^:dynamic *GAME-SECONDS-PER-TICK* 0.03)
 
+; ROBOT-RANGE-X and -Y are in meters
+(def ROBOT-RANGE-X 256.0)
+(def ROBOT-RANGE-Y 256.0)
 
diff --git a/src/robotwar/core.clj b/src/robotwar/core.clj
index a5b5214..dba5cb0 100644
--- a/src/robotwar/core.clj
+++ b/src/robotwar/core.clj
@@ -14,7 +14,7 @@
 (def progs 
   (repeat 3 (:moving-to-spot test-programs/programs)))
 (def world
-  (world/init-world 256.0 256.0 progs)) 
+  (world/init-world progs)) 
 (defn combined-worlds [] 
   (world/build-combined-worlds world))
 (defn worlds-for-terminal-display [fast-forward] 
diff --git a/src/robotwar/handler.clj b/src/robotwar/handler.clj
index 6c327a9..a3cae52 100644
--- a/src/robotwar/handler.clj
+++ b/src/robotwar/handler.clj
@@ -25,7 +25,7 @@
 (def progs 
   (repeat 3 (:moving-to-spot test-programs/programs)))
 (def world
-  (world/init-world 256.0 256.0 progs)) 
+  (world/init-world progs)) 
 (defn combined-worlds [] 
   (world/build-combined-worlds world))
 
diff --git a/src/robotwar/terminal.clj b/src/robotwar/terminal.clj
index 3591faa..b73433c 100644
--- a/src/robotwar/terminal.clj
+++ b/src/robotwar/terminal.clj
@@ -23,13 +23,13 @@
 
 (defn arena-text-grid
   "outputs the arena, with borders"
-  [{:keys [width height robots]} print-width print-height]
+  [{robots :robots} print-robot-range-x print-robot-range-y]
   (let [horiz-border-char "-"
         vert-border-char "+"
-        header-footer (apply str (repeat (+ (* print-width 3) 2) horiz-border-char))
-        scale-x #(* % (/ print-width width))
-        scale-y #(* % (/ print-height height))
-        field (for [y (range print-height), x (range print-width)]
+        header-footer (apply str (repeat (+ (* print-robot-range-x 3) 2) horiz-border-char))
+        scale-x #(* % (/ print-robot-range-x ROBOT-RANGE-X))
+        scale-y #(* % (/ print-robot-range-y ROBOT-RANGE-Y))
+        field (for [y (range print-robot-range-y), x (range print-robot-range-x)]
                 (or (some (fn [{:keys [idx pos-x pos-y]}]
                         (when (near-point [(scale-x pos-x) (scale-y pos-y)] [x y])
                           (str "(" idx ")")))
@@ -38,7 +38,7 @@
     (str header-footer
          "\n" 
          (join "\n" (map #(join (apply str %) (repeat 2 vert-border-char))
-                         (partition print-width field))) 
+                         (partition print-robot-range-x field))) 
          "\n" 
          header-footer)))
 
@@ -56,12 +56,12 @@
 
 (defn animate
   "animates a sequence of worlds in the terminal"
-  [initial-worlds print-width print-height fps]
+  [initial-worlds print-robot-range-x print-robot-range-y fps]
   (let [frame-period (time/millis (* (/ 1 fps) 1000))
         starting-instant (time/now)]
     (loop [[world :as worlds] initial-worlds
            frame-start starting-instant]
-      (println (arena-text-grid world print-width print-height))
+      (println (arena-text-grid world print-robot-range-x print-robot-range-y))
       (display-robots-info world (time/interval starting-instant frame-start) fps) 
       (let [desired-next-frame-calc-start (time/plus frame-start frame-period)
             this-instant (time/now)
diff --git a/src/robotwar/world.clj b/src/robotwar/world.clj
index e05a7e7..9fbd2d0 100644
--- a/src/robotwar/world.clj
+++ b/src/robotwar/world.clj
@@ -1,21 +1,20 @@
 (ns robotwar.world
-  (:use [clojure.string :only [join]])
+  (:use [clojure.string :only [join]]
+        [robotwar.constants])
   (:require [clj-time.core :as time]
             [clj-time.periodic :as periodic]
             [robotwar.robot :as robot]))
 
 (defn init-world
   "initialize all the variables for a robot world."
-  [width height programs]
-  {:width width
-   :height height
-   :shells []
+  [programs]
+  {:shells []
    :robots (vec (map-indexed (fn [idx program]
                                (robot/init-robot 
                                  idx 
                                  program 
-                                 {:pos-x (rand width)
-                                  :pos-y (rand height)
+                                 {:pos-x (rand ROBOT-RANGE-X)
+                                  :pos-y (rand ROBOT-RANGE-Y)
                                   :aim 0.0
                                   :damage 100.0}))
                              programs))})