You cannot step into the same river twice, and you cannot step through a portal unchanged. The act of deconstructing your atoms in one reality and reassembling them in another leaves marks.
The Price of Passage
Portal Sickness
Every time a character travels through a portal, they must make a Constitution Save (TN 12).
- Success: No ill effects.
- Failure: Gain the Disoriented condition for 1 hour (Disadvantage on Perception/Initiative).
- Critical Failure (Natural 1): Roll on the Portal Side Effects Table below.
Transformation Types
Physical Mutations (Somatic)
The body adapts to the destination before the mind does.
- • Skin Shift: Skin changes color or texture (scales, bark, glass).
- • Eye Glow: Eyes emit light matching the portal's color.
- • Weight Change: Character becomes lighter or heavier by 20%.
Duration: Usually 1d4 days, sometimes permanent.
Mental Echoes (Psychic)
The mind processes the infinite for a split second.
- • Memory Leak: Forget the last 24 hours.
- • Language Swap: Can only speak a language you didn't know before.
- • Emotion Lock: Stuck feeling one emotion (fear, joy, rage) for hours.
Temporal Distortion (Chrono)
Time is not a straight line in the tunnel.
- • The Lag: You arrive 1d6 hours after your party.
- • The Skip: You arrive 1d6 minutes before you left (Paradox!).
- • Aging: You age or de-age by 1d10 years.
Portal Side Effects Table
| d20 | Effect | Duration |
|---|---|---|
| 1 | Molecular Instability: Take 1d4 damage whenever you move more than 10ft. | 1 Hour |
| 2-4 | Technicolor Vision: You see colors that don't exist. Disadvantage on Ranged Attacks. | 1d4 Hours |
| 5-8 | Static Charge: You shock anyone you touch (1 damage). | 24 Hours |
| 9-12 | Whispering Aura: You hear voices from the portal constantly. -2 Perception. | Long Rest |
| 13-16 | Gravity Flux: Your jump distance is tripled. | 1 Hour |
| 17-19 | Phase Shift: You can walk through one solid wall (once). | Until Used |
| 20 | Portal Touched: Gain +1 Willpower permanently. Your eyes turn solid gold. | Permanent |