Sentient

Some are a hive: a single organism grown across a surface until the surface is one body, thinking with its whole mass. Others were never alive in that sense but are aware, on the Elementari pattern, a reading the Solir hold and the Aurelion Sector's registry rejects. Either way the world reacts to what happens on it: weather shifts in response, routes close, and a party that was welcome can become unwelcome with no sign.

Planetary environment

Crossing it

Navigate: DC 14
Forage: DC 6
Notice: DC 14

A route exists only while the world allows it. Foraging is easy while the world is willing and impossible when it is not.

Exposure

Rift Flux

Ambient Rift Energy at a high, unstable density, where channeling is stronger and less reliable.

WIS save, DC 13. End of each hour. Your next spell attack roll has disadvantage, or the target of your next spell that forces a saving throw has advantage on it. Roll once on the Surge Table.
- Dense field
  
  A spell cast here that deals damage or restores hit points adds its level to one of its damage or healing rolls, and a cantrip adds 1. A spell that does neither gains nothing. The bonus cannot be declined.
- Unstable
  
  A natural 1 or 2 on a spell attack roll, a target's natural 19 or 20 on a saving throw against a spell, and any failed concentration save each roll on the Surge Table in the GM's Manual.
- Instruments
  
  Anything calibrated against a stable Rift background reads wrong. Navigation, dating and detection checks that rely on one have disadvantage.
- Warded
  
  A ward, a null field or a feature naming Rift density removes the save and the Surge rolls. The damage and healing bonus goes with them.

In play

Observed

The world observes all of its surface. Stealth checks against the world fail, and every native creature knows the party's position from the moment it lands.
Disposition

The world holds a disposition toward the party from Welcoming to Hostile. Welcoming halves travel DCs and forage times; Hostile doubles them and makes the weather an active opponent.
Shifting terrain

Terrain shifts to open or close a route between one crossing and the next, so a chart of a Sentient world records only the routes the world allowed.
Rift-touched

Rift Flux applies. The effects of the world's own activity and of the Rift cannot be told apart.

Regions on it

Subterranean Everything under the surface, with no light, no weather, and a route set by what the rock allows.
Wetland Saturated ground between land and water, slow to cross and poor underfoot, with better cover than either.
Woodland Temperate forest and scrub with short sightlines and dense cover.