This ordinary-looking manuscript details the means by which a magic user may summon an otherworldly entity and bind it to his/her service. The caster may be aided by up to 5 other participants. For the purposes of this description, we will refer to a single “caster.” The additional participants can be of any class (they don’t have to be spellcasters).

There are dozens (perhaps even hundreds) of such Tracts, and each contains different material. The player must roll to determine the necessary components, the nature of the conjured entity, and so on. The player rolls percentile dice, then adds the combined number of levels and Intelligence modifiers¹ for the 1-6 characters who are participating in the ritual.

After a Tract is used, and a creature is summoned, the Tract is no longer usable; it disintegrates, and attempts to replicate the ritual will have no result. Additional Tracts may be discovered; for each one, results must be rolled anew.

For every one of the following sections (Ritual Type, Components, and so forth), the player must roll percentile dice, add the caster’s level, add the levels for all of the other characters who are helping the caster, and add all Intelligence modifiers for the characters. The higher the player’s roll, the more beneficial the outcome. A natural 01 roll is always treated as an 01, regardless of how many bonuses there are; a natural 100 is always treated as such, regardless of how many penalties the caster has accrued.

• Ritual Type – In this section, the tome describes the nature of the ritual. In each case, a human victim must be killed in a specific manner. Care must be taken that the necessary components (the victim’s body parts, for example) are not damaged. If they are, and the casters proceed, then subtract 1d20 from each subsequent roll.
• Components – Here, the text explains which components must be procured and added to the body parts of the murdered victim. Some of these components will be costlier than others; in general, the higher the roll, the lower the cost of the items. If the components are insufficient (for example, using silver coins instead of a bar of silver), then subtract 1d20 from each subsequent roll.
• Body – This section provides a basic description of the monster’s frame.
• Appendages – These additional limbs or organs may provide the creature with bonuses or penalties. As before, high rolls are preferable.
• Scent – Because the olfactory bulb is part of the limbic system, the part of the brain associated with memory and feeling, a list of scents has been provided. The creature may exude a pleasant aroma, or it may emit a heinous reek of putrefaction.
• Personality – This section describes the monster’s disposition towards the caster. It may be affectionate, or it may be filled with hate (and serve only because it must).
• Hit Points
• Armor
• Attacks
• Damage
• Movement
• Morale
• Abilities – These are bestowed upon the monster and the caster(s), and remain in effect as long as the creature is alive. Spells learned by the caster(s) are treated like ordinary spells, except that they can be cast by any character, regardless of class. Each spell is usable once (per caster). These spells are forgotten once the creature is gone. Bonuses are cumulative.
• Compulsions – Entities summoned by the Tract of Teratology are compelled to perform specific actions each day. If the entity does not satisfy its Compulsion on a daily basis, it can no longer access its powers, and its caster (or casters, if there were more than one) will suffer Penalties.
• Proximity – Some entities must satisfy their Compulsions by themselves, without assistance. Others will allow their casters to help, and yet others will permit casters to do the dirty work instead. For example, an entity that must feed on the flesh of murderers may allow the casters to do it instead, while the monster watches; it may even allow them to do it while it waits elsewhere, then return to describe the event to the monster, which is happy to experience this satisfaction vicariously.
• Penalties – During each 24-hour period, the entity’s Compulsion must be satisfied to the Referee’s satisfaction. If not, then the player must roll on the Penalties table, and all casters who were present at the the ritual will suffer the ill effects described there.
• Duration – The number of days that the entity will remain in this world before returning to its own (at which point the player must roll on the Aftermath table).
• Aftermath – When the Duration has elapsed, the monster will disappear, based on the results of this table.

¹ For characters using 2nd-edition rules, this is equal to the number of bonus paths granted by his Knowledge score.