--- a/src/rps.erl	Sun Mar 02 22:10:59 2014 +0900
+++ b/src/rps.erl	Sun Mar 02 22:41:13 2014 +0900
@@ -6,6 +6,7 @@
 -define(BOTS, [fool, copycat, gambler]).
 
 go() ->
+    register(nickserv, spawn_link(rps_nickserv, nickserv, [])),
     register(lobby, spawn_link(?MODULE, lobby, [])),
     register(counter, spawn_link(?MODULE, counter, [])),
     register(printer, spawn_link(?MODULE, printer, [])),

--- a/src/rps_bots.erl	Sun Mar 02 22:10:59 2014 +0900
+++ b/src/rps_bots.erl	Sun Mar 02 22:41:13 2014 +0900
@@ -3,6 +3,7 @@
 -export([fool/0, copycat/0, gambler/0]).
 
 fool() ->
+    nickserv ! {nick, self(), "fool"},
     lobby ! {join, self()},
     fool(joined).
 
@@ -24,6 +25,7 @@
     end.
 
 copycat() ->
+    nickserv ! {nick, self(), "copycat"},
     lobby ! {join, self()},
     copycat(joined).
 
@@ -43,6 +45,7 @@
     end.
 
 gambler() ->
+    nickserv ! {nick, self(), "gambler"},
     lobby ! {join, self()},
     gambler(joined).
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/rps_nickserv.erl	Sun Mar 02 22:41:13 2014 +0900
@@ -0,0 +1,20 @@
+-module(rps_nickserv).
+-export([nickserv/0, whois/1]).
+
+nickserv() ->
+    nickserv(dict:new()).
+
+nickserv(Nicknames) ->
+    receive
+        {nick, Who, Nickname} ->
+            nickserv(dict:store(Who, Nickname, Nicknames));
+        {whois, Pid, Who} ->
+            Pid ! {ok, dict:fetch(Who, Nicknames)},
+            nickserv(Nicknames)
+    end.
+
+whois(Who) ->
+    nickserv ! {whois, self(), Who},
+    receive
+        {ok, Nickname} -> Nickname
+    end.