Many players/scripters have been actively looking for a way to detect rare items dropped by monsters, here's our investigations so far, if you can shed some light, feel free to post a comment in the Discussions section at the bottom.

Elfbot doesn't have a way to Look an item so we can't see if it is Rare/enchanted.

Elfbot can see an item ID but not from the inventory, from the floor, so you'd need to drop it first. Still, knowing the item ID tells us nothing because normal and rare items share the same ID.

When a creature drops a rare item, a spark (similar to the invisibility one) is shown, this is what we detect on ElfBot just like when ElfBot detects a creature going invisible.

The most that this does is to play a sound, so it's not fully automatic but can help if you are non/semi-AFK.

1. Go to Targeting and add your desired creature (e.g. Demon)
2. Now add another creature named Reveal and place it on top of Demon
3. Set the following settings:
   1. Attack: No Action
   2. Play Alarm: On
   3. HP% Range: 0 to 100

Source: here and here.

By putting the item on the market, we can then read the “You put ITEMNAME on the market for 123 Noxious Tokens”, then, we know that mostly all rare items have an “ of ” in the name, so we could detect rare items. We could then quickly return it.

The problem is that you will spam the market with offers and annoy players/GMs.

An alternative is to sell the item with an invalid transaction: !market sell,asdf,asdf which doesn't post it to the market but you get the item name in the chat, the problem here is that the text is red and we haven't found a way to detect red text.

There's this !stats command that tells you the item boosts you have right now, by comparing the Stats before and after equipping the item, you could check for any differences and if so, it means the item has enchanted properties.

The problem is that the text is red and we haven't found a way to detect red text.

Equip the item and detect Speed, Health, Mana and +Magic Level items by checking changes in $self variables (e.g. $self.speed).