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Guide.md

@@ -46,4 +46,15 @@ If a condition is true at the moment, the phrase is shown. If a condition is nil
 
 Now the third phrase is initially out. If the player chooses the second one, it hides away and the third shows up. The conditions can also be functions - they have to return a boolean (`true` or `false`). Conditions can be as complex as you want it, they have the complete game state to check.
 
-What's also important here is that: conditions are checked on every look in the room. The player can activate an inventory object and have a different set of options immediately. The `choice` object can react even at INSTEAD preferences change — everything you can think of. It's often much easier than setting every phrase on and off with direct instructions.
+What's also important here is that: conditions are checked on every look in the room. The player can activate an inventory object and have a different set of options immediately. The `choice` object can react even at INSTEAD preferences change — everything you can think of. It's often much easier than setting every phrase on and off with direct instructions.
+
+## rndstr module
+A very short module that gives you a string randomization function. Example usage:
+
+    rndstr({
+      'Ow!',
+      'Oh!',
+      'Holy pink horse in the sky!'
+    });
+
+This results in a random string from the table.