4E Planes of Chaos Mechanics

This is the second installment of my 4E mechanics for the Great Wheel, dealing with the chaotic planes: the Abyss, Pandemonium, Limbo, Ysgard, and Arborea. As one would expect, the basic inspiration comes from the original 2E Planes of Chaos product.

I think the mechanics for Pandemonium turned out quite interesting – the 4E disease track is perfect for the discrete stages in wind madness as presented in Planes of Chaos. Strangely, though, I didn’t feel too inspired about the less chaotic planes – the Abyss and Arborea - so I would really appreciate some suggestions for those.

Arborea

As Arvandor (p90), though with original layer-structure and environment.

Inveiglement: Attacks with the charm or illusion keyword gain a +1 bonus to the attack roll. This trait is directly from 4E MotP.

Emotions run Wild: Saves against effects with the fear or charm keyword take a -1 penalty.

Reckless Moods: In social Skill Challenges, Charisma-based checks grant 2 successes when passed and 2 failures when failed.

Surge of the Heart: Once per day, upon using an attack power, any creature can add the Invigorating keyword to the power as a Free Action.

Ysgard

Gravity: Elemental buoyancy with regards to earthbergs (Motp p10), otherwise normal.

Mutability: Divinely mutable (deities control their own environs). Earthbergs also move of their own accord and the fires beneath them burn endlessly.

Eternal Rebirth: If a petitioner of Ysgard is killed on the plane it is reborn the next morning.

Seize the Moment: When an Action Point is spent to take another action, the character gains +1 to any one roll used during the action.

Earthberg Collision: Earthberg’s occasionally drift into each other, though the impact is usually mild. Treat as a heroic tier blaster hazard that targets Fortitude, deals low normal damage (DMG p42) and knocks targets prone.

Spirit of Heroes: Once per day, a bloodied creature can regain the use of its Second Wind.

Flames of Muspelheim: The earthbergs of Muspelheim have flames on the upper rather than lower side. Treat most open environment as a level 13 field of everflame (DMG p92): +16 vs. Fortitude, 1d10+5 fire damage and ongoing 10 fire (save ends), and half damage on miss.

Limbo

Gravity: Subjective (MotP p10).

Mutability: Unstable (MotP p10). [Mechanics for influencing unstable planes at the end of this excerpt]

Primal Soup: Though Limbo features an abundance of ever-changing elemental pockets, most of the environment has a viscous consistency that is unbreathable and cuts visibility in half, but can be swum (though subjective gravity usually makes this option moot). The Soup is readily changeable, however, so the DC for a creature to alter the area it occupies is lowered by 10 (as per the Alter Area mechanic described under the Influence Unstable Plane section), and such a “personal bubble” can be sustained as a Minor Action while moving through unmodified Soup.

Elemental Hazards: Travelers in Limbo are frequently threatened by dangerous elemental terrain that suddenly moves, grows, or forms close by. Use the hazards described in the MotP p66-67 and 22.

Unpredictability: The DM rolls a d20 at the start of an encounter. Whenever any d20 roll unmodified comes up that number during the encounter, reroll and use the second result.

Pure Xaos: When an Action Point is spend to make an attack or skill check, add 1d12-6 to the roll.

Pandemonium

Gravity: Normal on Phlegethon, on other layers towards nearest earthen surface.

Mutability: Divinely mutable (deities control their own environs). The winds blow endlessly and changes strength and direction all the time. Their intensity is unconnected to the size of tunnels they blow through.

Winds of Pandemonium: Outside of the shelter of a sturdy structure, all of these detrimental effects are imposed by the howling winds: All creatures take a -5 penalty to Perception checks in Pandemonium. Flying creatures treat all squares as difficult terrain. Attacks with the thunder keyword deal half damage (ongoing thunder damage is not affected). Zones of any kind cannot be sustained. This trait is directly from 4E MotP.

Maddening Howls: The howling winds drive most residents mad to some extent if they live or travel frequently without considerate sheltering. For every 4 hours so exposed, the creature is subject to being stricken with Pandemonium Madness (see Planar Dangers).

Forceful Gales: The winds are often powerful enough to force creatures around if not completely blow them off their feet. Treat as a current as per DMG p45 (but also on land), adding 1d6 to the number of slided squares if the creature has jumped, flied, or been forced into the air. For even more intense winds, use a hazard that targets Fortitude, damages, pushes, and/or knocks targets prone (see Kinetic Wave on DMG p92 for a likely model).

Tunnel Ride: Since gravity at the center of a tunnel pulls equally towards the nearby surfaces, objects and brave/foolish creatures can ride the winds for a while before they are knocked towards a surface. When near such a center, creatures can attempt an Acrobatics check vs. DC 25 + speed of current to adjust accordingly. For each point by which they beat the DC they can slide a number of squares along the wind equal to the speed of the current and land in the direction they choose. For every 5 points they fail they take 1d10 damage and are knocked prone to a random surface.

The Styx: The Styx flows through Pandemonium, occasionally flowing in midair through the center of tunnels. It is less severe on this plane, however – the DM may want to delevel the hazard and lower the roll correspondingly (see Planar Dangers).

Abyss

Gravity: Normal

Slaughter: All damage dealt to and by a bloodied creature is increased by 2.

Death Comes Quickly: Death saving throws take a -1 penalty and creatures die after only two such failed saves.

Rule through Force: Intimidate checks gain a +1 bonus while Diplomacy checks take a -1 penalty.

Blood and Gore: Critical hits also deal ongoing damage 5 (save ends).