_NPCScan tracks seldom-seen rare mobs by proximity alone, making the old “<kbd>/targetexact …</kbd>” macros obsolete. It has the same range as those targeting macros, but you won't have to mash any buttons. Just go about your business and let _NPCScan alert you when it finds something.

Details

The Cache

This addon doesn't use nameplates or mouseover units to find rares. Instead, it checks your creature cache for the moment a rare mob is found. There is one catch to this technique however: Once a mob is “found”, _NPCScan won't be able to find it again until your cache is cleared.  If you find a rare mob's corpse—Dirkee for example—you would have to clear your cache before _NPCScan would find Dirkee again.  Thankfully, clearing your cache is a safe and simple matter.

Clearing Your Cache

To clear your cache, follow these straightforward steps:

1. Exit World of Warcraft.
2. Delete the “<kbd>Cache</kbd>” sub-directory inside your World of Warcraft folder.  For example on a standard Windows XP installation, you would delete the folder “<kbd>C:\Program Files\World of Warcraft\Cache</kbd>”.
   • Advanced users can delete “<kbd>C:\Program Files\World of Warcraft\Cache\WDB\enUS\creaturecache.wdb</kbd>” specifically to improve log-in times, where <kbd>enUS</kbd> is your language code.

<font color="red">Note: Windows Vista and Windows 7 users see this info if your cache isn't in the location above.</font>

That's it.  Log in after you've done that and you'd be able to find Dirkee a second time.  It's completely safe because WoW will recreate your Cache folder after you log in again.

Cache Warning

If a rare mob is already cached when you log in, _NPCScan will print a warning message with the names of those mobs.  If you see this message but still want to find the listed NPCs again, it's time to clear your cache by following the above procedure.  Otherwise, you can quit searching for those mobs using the Search options window detailed below.  You can suppress this log-in message using the main options pane, as well.

“Found” Alert

When a rare mob is found, _NPCScan alerts you by playing a loud and distinctive sound, making your screen pulse red, and displaying an animated targeting button.  To get a feel for what this alert looks and sounds like, try the “<kbd>Test Found Alert</kbd>” button in the addon's main Interface Options panel. (See the Options section below.)

Targeting Button

When clicked, the targeting button tries to target the most-recently-found mob.  You can also bind a key to hit this button. If the default button position isn't to your liking, you can move it while holding your <kbd><CTRL></kbd> key.

<font color="red">Note: The button cannot be shown during combat.  In the unlikely case that you do find a rare while fighting, the button will appear after you leave combat.  You will still hear the alert however, and the name of the mob will appear in your chat log.</font>

Options

_NPCScan's main options window can be accessed from the Interface Options menu.  This panel includes a “<kbd>Test Found Alert</kbd>” button, various ways to customize the alert sound, and an option to suppress cache warning messages on log-in.

New sounds can be added to the alert sound dropdown menu by installing <cite>SharedMedia</cite>-type addons.

Search List

The list of mobs that _NPCScan searches for can be modified easily through the Interface Options panel, however it comes pre-configured with most rare Outlands and Northrend mobs.  To access the mob list, type “<kbd>/npcscan</kbd>”.

Grayed out NPCs in a list aren't being searched for, either because they're cached or not needed for their achievement.

• The first tab available lists Custom NPCs that you can enter or remove manually.  NPCs that are already cached show a red “<kbd>X</kbd>” in the first column.  You can add or remove Custom NPCs with the <kbd>[+]</kbd> and <kbd>[-]</kbd> buttons at the bottom right.
• All other tabs control achievements like Bloody Rare and Frostbitten.  These tabs show an additional column on the right with green check marks for completed achievement mobs.  You may enable or disable tracking each achievement with its tab's checkbox.

The “<kbd>Search for completed Achievement NPCs</kbd>” checkbox at the top left of the pane allows you to keep looking for mobs you no longer need for achievements.

Finding NPC IDs

A mob's NPC ID is its unique identification number, and it can be found on sites like WowHead or WowDB.  For example, search for the mob “<kbd>Dirkee</kbd>” on WowHead and go to the mob's page.  That page's URL will look like “<kbd>http://www.wowhead.com/?npc=32500</kbd>”; <kbd>32500</kbd> is Dirkee's NPC ID.

Limitations

The only problem mobs for _NPCScan are tamable beasts.  Even when you run across the tamed version, _NPCScan gets tricked into thinking that mob is nearby.  In order to prevent those false positives, _NPCScan only shows alerts for tamable mobs in their original zones.  That is, if you spot Loque'nahak in Dalaran instead of Sholazar Basin where it usually patrols, _NPCScan would ignore it.  When one of these tamable mob false-alarms happens, you'll see a message in your chat window explaining why it got ignored.

Since this makes tamable mobs are so difficult to track, I suggest you fly to the tamable mob's zone first, clear your cache, and then search for it.  Any time you pass through a populated area like Dalaran, you risk filling your cache with popular rare pets.