MRAD System (5e Variant Rule)
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MRAD (Magical Radiation) System
When magical energies burn for too long, they can become stale, corrupted, toxic even. They poison the land around them beyond repair, corrupting denizens caught within into horrid abominations. Perhaps the blood of a dragon older than time spilled into a lake, transforming the wildlife into an energy-filled hellscape. Maybe the arcanums left over from an ancient war between Necromancers morphed an entire city into a wasteland worse than even the Shadowfell. This phenomena is known as Magical Radiation, or more commonly MRAD, and should not be trifled with.
MRAD Mechanics: RAD Score
The RAD score is a new score exclusive to the MRAD System, similar in concept to Sanity. The stat starts at 0, and certain things (Such as Unstable damage) can require a constitution saving throw or increase the stat by 1. When the score increases to 5 or more, the creature must make a DC 13 constitution saving throw or gain a Minor Mutation. At a score of 10 or more, the DC of the save increases to 15 and Major Mutations start to form. At 20 MRAD, the creature must make a DC 18 intelligence saving throw at the start of each of their turns or take 10d6 Unstable damage. The mutations will often depend on the source, but a table of various mutations is included later in this page.
MRAD Mechanics: Unstable Damage Type
The Unstable damage type is a representation of the radiation affecting a creatures body in violent ways. When a creature takes Unstable damage, it must make a constitution saving throw with a DC equal to the damage roll or 10 (Whatever is lower), or have their RAD stat increased by 1. Creatures with a Resistance to Unstable damage make the save at Advantage, creatures with an immunity to Unstable damage automatically succeed the save, and creatures with a weakness make the save at Disadvantage. Unstable damage is commonly an environmental effect, though monsters that deal it can exist (such as Grey Dragons).
MRAD Mechanics: MRAD Creatures
Creatures that are affected by MRAD over long periods of time can form into highly corrupted versions of themselves, just as unpredictable as the energies that tainted them. An example of this is the Grey Dragon, which are powerful draconids that have a breath weapon of pure, Unstable energy. Rather than a cone or line, the breath weapon of a Grey Dragon takes the form of a sphere centered on them, as the energy swirls and circles around them. Grey Dragons are highly adept at climbing and maneuvering Difficult Terrain, and often make their nests on areas inaccessible otherwise. Grey Dragons commonly scatter their hoarde within various hiding spots that their environment contains, never truly keeping it all in one spot. They can be any Chaotic alignment, or even Unaligned. Grey Dragonborn also exist.
List of MRAD Creatures
List of MRAD Creature Templates
List of MRAD Races
MRAD Mechanics: Mutations
Minor Mutations Table (1d100)
1-15: Osteoporosis You take double damage from all sources, and you lose any Resistances you may have.
16-20: Claws Your unarmed attacks deal Slashing damage and you gain a 15 foot climb speed, but you have Disadvantage on Dexterity (Sleight of Hand) checks.
21-25: Irradiated Blood When you are damaged by a spell effect or magical item, you radiate Dim Light in a 20 foot sphere for 1 minute, giving you disadvantage on Dexterity (Stealth) checks.
26-29: Enhanced Sight You gain Darkvision for 60 feet. If you already have Darkvision, increase it's range by 60 feet. You can see through Nonmagical darkness, but any Wisdom (Perception) checks made while doing so have a lose any proficiency or advantage you may have. Also, you gain disadvantage on saves relating to Blindness.
30-35: Minor Magic Sense You act as if you are constantly under the effects of Detect Magic cast at it's lowest possible level, but if you enter an Antimagic Field or have Dispel Magic cast on you, you have to make a flat DC 10 Wisdom saving throw or take 2d4 Force damage and become blinded for 1 round.
36-41: Arcanovorous When you use an unarmed attack against a creature with the Spellcasting feature, the creature must make a flat DC 10 Intelligence save. On a failed save, you regain 1 hit point and the target can only cast At Will spells or Cantrips until the end of your next turn. On a successful save, nothing happens. However, Exhaustion acts as if it is 1 level worse than it actually is for you.
42-48: Radiation Sickness Your DM chooses a Disease of their choice, and infects you with it. Unless you have the mutation cured, you cannot cure this disease. However, you also gain advantage on Constitution saving throws against other forms of Poison or Disease.
49-50: Minor Magic Manipulation You gain two cantrips and one 1st level spell of your choice from any class (they needn't be from the same class). Charisma is your spellcasting ability. However, you also gain a weakness to Force and Unstable damage.
51-55: Unstable Shield You can cast Shield at will once per day, and doing so gives you a temporary resistance to Unstable damage for the duration. However, once the duration is over, you create a Wild Magic Surge and must roll on the Wild Magic Table.
56-60: Unstable Bolt You gain the Eldritch Blast cantrip. However, your AC reduces by 1
61-71: False Gills You can breathe underwater and have a swim speed of 15 feet, but your Walking speed reduces by 5 feet.
72-100: Minor Dragon Breath You learn 1 of the following cantrips: Acid Splash, Cone of Cold, Fire Bolt, Poison Spray, Lightning Lure. However, you gain a weakness to the damage type the cantrip deals.
Major Mutations Table (1d100)