A wizard casting the shadow monsters spell uses material from the Demiplane of Shadow to shape semireal illusions of one or more monsters. The total Hit Dice of the shadow monster or monsters thus created cannot exceed the level of experience of the wizard; thus, a 10th-level wizard can create one creature that has 10 Hit Dice, two that have 5 Hit Dice, etc. All shadow monsters created by one spell must be of the same sort. The actual hit point total for each monster is 20% of the hit point total it would normally have. (To determine this, roll the appropriate Hit Dice and multiply the hit points by.2. Any remainder less than.4 is dropped—in the case of monsters with 1 or fewer Hit Dice, this indicates the monster was not successfully created—and scores between.4 and 1 are rounded up to 1 hit point.)

Those viewing the shadow monsters are allowed to disbelieve as per normal illusions, although there is a -2 penalty to the attempt. The shadow monsters perform as the real monsters with respect to Armor Class and attack forms. Those who believe in the shadow monster suffer real damage from their attacks. Special attack forms such as petrification or level drain do not actually occur, but a subject who believes they are real will react appropriately.

Those who roll successful saving throws see the shadow monsters as transparent images superimposed on vague shadowy forms. These are Armor Class 10 and inflict only 20% of normal melee damage (biting, clawing, weapon, etc.), dropping fractional damage less than.4 as done with hit points.

For example: A shadow monster griffon attacks a person who knows it is only quasi-real. The monster strikes with two claw attacks and one bite, hitting as a 7-Hit Die monster. All three attacks hit; the normal damage dice are rolled, multiplied by.2 separately, rounded up or down, and added together to get the total damage. Thus, if the attacks score 4, 2 and 11 points, a total of 4 points of damage is inflicted (4 x.2 =.8 [rounded to 1], 2 x.2 =.4 [rounded to 1], 11 x.2 = 2.2 [rounded to 2]. The sum is 1 + 1 + 2 = 4).