i20 Essentials

These rules are for compatibility with d20 System as represented in the Basic Rules presented in The ©Players Handbook™.

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Incarna Approach: All of the principles and approaches of the Incarna game system have been followed with the i20 branch, as announced on the web site and Facebook.

Magic/Spell Changes

Empowered Magic removes the “check each round” aspect of spells. Once a spell save is failed, the primary effects are failed for the duration. Spell casters need to abide by Casting Constraints for rules on casting in armor.

Rule of Averages/Quality of Results

Hit Points, damage, and other factors use a measured outcome scale for damage or effect. That average (Simple Result) is to be used unless noted in materials.

  • Disastrous: (Critical Failure) The worst possible result (usually a “1” on a D20 – the target takes full damage on a save, stumbles and may fall, or has some other calamitous result) – GM Narration will handle this.
  • Simple: (Average) The check was a minimal amount of what was needed to succeed (ex: A sword doing 2d6 does 7 damage + adjustments).
  • Major: (Full) The check was 20% or more than what was needed (5 or more on D20) for success or double that (10 or more on D20) for failure. Base damage and/or effects are maximum (ex: A sword doing 2d6 does 12 damage + adjustments).
  • Extraordinary: (Critical Success) The best possible result (usually a “20” on a D20). Base damage is double maximum and effects are maximized. Such attacks can also cause Wounds (see hereafter).

Attribute/Ability Scores and Sanity

Incarna [iD20] uses 7 scores, adding Sanity to the standard 6 of d20. The Sanity attribute is used to make horror/terror/fear checks with (see 5E DMG p.264). It replaces other Ability based saving throws (usually Wisdom and Charisma) for the same type of effects. Generally, no race should get a modification to Sanity. It is generated however each GM desires it to be depending on the method used (points, rolls, etc.) or simply assume an 11 as a base (10 for half breeds or other more chaotic types).


All things have Essence, with higher order beings having more. Essence follows the normal explanation of it in Incarna – Bonds of faith and patronage, Attunement (Essence limits the amount of things/items one can attune to, not the d20 limit), and Aptitude (optional; enables strict transcendence of class rules) will require it. Many classes require the character sacrifice a small amount of Essence in order to be able to use their powers on The Pattern.

  • Attunement and Bindings all require Essence (minimum 1); it returns at 1/Short Rest once it is no longer used for this.
  • Essence can be used to barter for powers and enhancements with powerful creatures (like “Selling your soul”) capable of granting such.
  • Essence is calculated as: (Sanity) + Proficiency Bonus + [positive] Ability Modifiers for all other starting ability scores. As these change, so too does the pool of Essence the character has.

Health, Resting and Recovery

Damage and Recovery are more lethal. A Short Rest is a full night of rest, after which time characters regain 1 + their Constitution bonus (min of 1) in HP. Hit Dice are not rolled for healing – HP represent the real physical punishment a character can take. Exhaustion is recovered at 1 measure per Short Rest. A Long Rest is a full week of rest (after which time character regains their full HP). Wounds (see hereafter) can inhibit this, and quality of care and conditions can adjust this. The normal Survival Rules for Incarna apply otherwise.

  • Temporary HP: Temporary HP are lost when used or after a Short Rest if the effect granting them does not specify.
  • Starting HP: Characters start with only an average Hit Dice at first level, unless noted.
  • Fatigue Damage: Fatigue damage is light stress and strain. If it drops a character below 1, they become unconscious – it cannot kill. Unless noted, it is completely healed after a Short or Long Rest.
  • Hard Damage: Hard Damage is damage that heals at the rate of 1 per Long Rest. Very few effects produce Hard Damage.
  • VITALITY: A collection of effects that can either be positive (imbued) or negative (inhibited). A character can possess multiple (i.e. cumulative) measures of effects.

Damage Resistance: Effects like Barbarian Rage, that grants resistance, also applies to magical attacks of the same type unless they have additional damage types in the same strike, are described as preventing this (powerful weapons/effects), or under the effect of the Magic Weapon spell.

Resilience of Items

The Incarna basic Resilience rules for items are used. Every point of Resilience can be used to shift the Quality of Result down, at the expense of using the item to take the blow and reduces its effectiveness. For example, a medium light shield has 1 Resilience – it can absorb 1 blow. Resilience can be restored by an appropriate crafter or technology, usually for a cost.


A character who is “Wounded” suffers immediate (damage) and longer term effects. The source of the wound may describe other specific effects, but always cover the following: 1) The target gains a level of Exhaustion (cumulative, to a maximum of 5 – i.e. cannot kill), 2) Their sequence of Death Saves starts with one failure. They lose any advantage on their physical ability checks, and lose 5′ of movement. A character automatically becomes Wounded when:

  • They take a Critical Hit – Minor Wound
  • They drop to 0 hit points (of non-fatigue damage) but are not killed outright – Major Wound; any healing spell that is equal to or more than the negative HP value that is cast upon the target in the same round, will return them to 1 HP without the Wounded condition.

Minor Wound: The effects of 1 Minor Wound are negated after a Short Rest is completed; Additional ones each take a Short Rest.

Major Wound: The effects of 1 Major Wound are negated after a Long Rest is completed; Additional ones each take a Long Rest. Greater Restoration can heal one Major Wound or all Minor Wounds.

  1. -1 Strength
  2. -1 Constitution
  3. -1 Dexterity
  4. -1 Physical Attacks
  5. -1 Intelligence
  6. -1 Wisdom
  7. -1 Charisma
  8. -2m/5′ Movement
  9. 1 permanent failed death save
  10. -1 HP permanent

Grievous Wounds can only be healed with Regenerate spell, which only completes after a full Long Rest.

Universal Class Specific Changes

If not covered elsewhere in this synopsis, the following changes also apply:

Advancement on Story: It follows the general Story Advancement guidelines of average challenge, levels 3-8 for d20™ versions. Instead of character powers and health regaining swiftly, that pace is slowed to something more realistic following the “Gritty Realism” principles.