diff --git a/src/main/java/com/samskivert/util/Randoms.java b/src/main/java/com/samskivert/util/Randoms.java
index 04cc023f..24956414 100644
--- a/src/main/java/com/samskivert/util/Randoms.java
+++ b/src/main/java/com/samskivert/util/Randoms.java
@@ -1,5 +1,22 @@
 //
 // $Id$
+//
+// samskivert library - useful routines for java programs
+// Copyright (C) 2001-2010 Michael Bayne, et al.
+// 
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 
 package com.samskivert.util;
 
@@ -11,6 +28,10 @@ import java.util.Random;
 
 /**
  * Provides utility routines to simplify obtaining randomized values.
+ *
+ * Each instance of Randoms is completely thread safe, but will share an underlying
+ * {@link Random} object. If you wish to have a private stream of pseudorandom numbers,
+ * use the {@link #with} factory.
  */
 public class Randoms
 {
@@ -71,6 +92,8 @@ public class Randoms
 
     /**
      * Returns true approximately one in n times.
+     *
+     * @throws IllegalArgumentException if <code>n</code> is not positive.
      */
     public boolean getChance (int n)
     {