CRITICAL HIT: A natural 20 on an attack roll inflicts maximum damage plus another normal roll of the damage dice.
CRITICAL FUMBLE: A natural 1 on an attack roll causes a complication, such as dropping a weapon, losing balance, or exposing oneself to a counterattack.
OVERKILL DAMAGE: When an attack kills an enemy, excess damage carries over to another adjacent enemy with an Armor Class that could have been hit by the initial attack’s roll. This overkill continues until the damage fails to kill an opponent or there are no more enemies within weapon reach.
AUTOMATIC CLEAVE: When an attacker reduces an enemy to 0 hit points with a melee attack, they may immediately attack another enemy within reach.
SHIELD SACRIFICE: A character may allow a shield become ruined to negate all damage from one successful attack. Sacrificing a shield may also negate damage from dragon breath, explosions, or certain magical effects, at the GM’s discretion. Magical shields might survive several such sacrifices.
EVASION: A character can sacrifice taking any actions in a round to instead parry and dodge attacks, gaining +3 AC against incoming melee attacks. If cover is available (i.e. trees, stalagmites, crowds), this +3 AC bonus applies to incoming ranged attacks as well.
TWO-WEAPON FIGHTING: A character wielding two weapons may make an additional attack each round, typically with a -3 penalty to both attacks.
NATURAL HEALING: Characters recover their Constitution modifier in hit points per night of rest (at least 1 h.p.), or regain a number of hit points equal to their Level after a full day of rest.
EMERGENCY AID: A character at 0 hit points lingers unconscious and dying for 1 round per Level until “permanently” dead. Any magical healing (cure light wounds, healing potion) given during this time restores the character to life.
CANTRIPS: Magic-Users can perform minor magical effects at will, such as lighting candles, cleaning objects, or causing a book to float as if being held. (As a rule of thumb, any one action the magic-user could have done by normal means instead.) The magic-user may also create harmless illusions that fit in the palm of a hand.
FLEXIBLE SPELL PREPARATION: Spellcasters prepare a selection of spells but may use available spell slots to cast any of those prepared spells, rather than memorizing each spell individually.
POISON
* Causes ## damage per hour for 1d6+## hours. A successful saving throw versus poison reduces damage by half for that hour.
* More deadly poisons cause damage and saving throws per minute instead of hour.
* The correct antidote immediately ends harm from that poison.
DISEASE
* To avoid infection and resist symptoms, a creature adds its Constitution modifier to the saving throw.
* Per exposure, a creature must succeed at a saving throw vs. death to avoid infection.
* An active disease causes obvious symptoms in 1d6 days (and in some cases, 1d6 hours).
* Disease symptoms count as a hindrance (-3 to tasks) until the infected succeeds at a saving throw versus death. Check once each day to resist suffering from symptoms.
* For deadly diseases, each failed saving throw reduces the infected’s maximum hit point total by half (down to 50% after first failed save, 25% after second, 12% third, and so forth; round down). At less than 1 hit point, the infected creature dies.
ENERGY DRAIN
* Permanently reduces a creature’s maximum hit points by an amount equal to the hit dice of the source. A creature reduced to 0 hit points instantly dies.
CHARM (rules-as-written reminders)
* A creature can only be charmed by one source at a time, obeying the most recent charmer.
* A charmed creature cannot cast spells or use magic items.
* A charmed creature will not harm the source of the charm.
* Creature is compelled to keep the source of the charm from harm.
* Creature obeys simply commands given by the source of a charm.
* A charmed creature instantly breaks free from a charm when the source of the charm is killed, or when other magic is used to dispel the charm.
PARALYSIS (rules-as-written reminders)
* A paralyzed creature cannot move or speak, but remains fully aware of surroundings.
* A typical case of paralysis lasts for 1d6+1 minutes.
* A cure light wounds spell can instantly remove paralysis in place of restoring any hit points.
FIRE
* Thrown flask of oil: 1d6+1 damage per round for 2 rounds