# Defensive item
When a monster is generated, there is a chance that it will be given a defensive item to protect itself from hostile adventurers. This will happen if the monster's level equals or exceeds the roll of a d50.[1]
The following monster types are ineligible for defensive items:

Animals
Monsters with explosion attacks
Mindless monsters
Ghosts and shades
Keystone Kops of any rank
In addition, regular soldiers have a 12/13 chance of missing out on the defensive item roll.[2]
If chosen to receive a defensive item, the monster selects and rolls a die according to its difficulty:

Difficulty
Roll

3 or less
d8

4–6
d9

7–8
d10

9 or more
d11

The die roll determines the item, as shown by the following table:[3]

Roll
Outcome

1–2
scroll of teleportation

3
scroll of create monster

4
potion of healing

5
potion of extra healing

6
potion of full healing(potion of sickness for Pestilence)

7
wand of teleportation (33%) or scroll of teleportation (67%)(reroll up to 2 times if no-teleport level)

8
wand of digging(nothing for floating eyes)[8]

9
wand of create monster (33%) or scroll of create monster (67%)

10
(teleport item, same as case 7)

11
(create-monster item, same as case 9)

Use
Non-animal, non-mindless monsters will use defensive items when they are within 5 squares Euclidean distance of you and they have a problem that needs fixing:[9]

Non-cursed unicorn horn is used by a monster with hands when confused, stunned, or blind[10].
Lizard corpse or tin is eaten when confused or stunned.
A healing item (potion of full healing, extra healing, or healing, in that order[11]) is used by a monster with hands that has been blinded.[12]
Monsters will only do the following if their HP is less than 1⁄5 of their maximum when your experience level is less than 10, 1⁄4 HP when XL is between 10 and 13, or 1⁄3 when your XL is at least 14:[13]
Peaceful monsters will quaff a healing potion if they have hands, but not attempt to use any other defensive items.
Non-peaceful monsters that are not stuck or immobile will attempt to flee through stairs or traps (teleporters and holes).
Mercenaries will use a bugle if there are more mercenaries within 3 squares that can be woken up.[14]
The following items will be used by a monster with hands:[15]
wand of digging, except by shopkeepers, guards, or priests; in Sokoban; or where digging is ineffective.
wand or scroll of teleportation, unless the monster knows that the level is no-teleport.
shopkeepers in their shop, guards, and priests will not use cursed scrolls of teleportation.
potions of full healing, extra healing, or healing; wand or scroll of create monster.
See Also
Monster starting inventory
Miscellaneous item
Offensive item
Death drop
References

↑ src/makemon.c in NetHack 3.6.6, line 794

↑ src/makemon.c in NetHack 3.6.6, line 791

↑ src/muse.c in NetHack 3.6.6, line 1014

↑ src/shknam.c in NetHack 3.6.6, line 655

↑ src/vault.c in NetHack 3.6.6, line 387

↑ src/priest.c in NetHack 3.6.6, line 239

↑ src/muse.c in NetHack 3.6.6, line 536

↑ The code indicates that shopkeepers, guards, and temple priests are also not to receive a wand of digging, but mtmp-&gt;{isshk,isgd,ispriest} are only set after makemon() is called,[4][5][6] thus they are eligible to receive it.  This has no practical gameplay effect (other than the possibility of getting wands of digging if you kill them) because these monsters will not use wands of digging.[7]

↑ src/muse.c in NetHack 3.6.6, line 325

↑ src/muse.c in NetHack 3.6.6, line 348

↑ src/muse.c in NetHack 3.6.6, line 302

↑ src/muse.c in NetHack 3.6.6, line 393

↑ src/muse.c in NetHack 3.6.6, line 399

↑ src/muse.c in NetHack 3.6.6, line 490

↑ src/muse.c in NetHack 3.6.6, line 523