Every so often, players do something that suddenly introduces the PCs (and potentially the DM) to the Astral Plane. There are a number of events that can abruptly bring an adventurer (or their belongings) to the Astral plane to the surprise of the GM and players alike:
- Dimension Door: If the magic-user arrives in a place which is already occupied by a solid body, he or she remains in the Astral plane until located by some helpful creature willing to cast a Dispel Magic upon the person, for he or she is stunned and cannot successfully perform any spell casting.
- Duo-Dimension: The magic-user has a portion of his or her existence on the Astral plane when the spell is in effect, and he or she is subject to possible notice (1 in 20) from creatures on the Astral plane (see Appendix C in the DMG). If noticed, it is 25% probable that the magic-user will be entirely brought to the Astral plane by attack from the astral creature.
- Word of Recall: For each plane that the cleric is removed from the plane of his or her designated sanctuary, there is a 10% cumulative chance that the cleric will be lost in the intervening Astral spaces.
- If a Bag of Holding is sundered or destroyed because it failed a saving throw the contents are drawn into the Astral plane.
- If a Bag of Holding is placed within a Portable Hole, a rift to the Astral plane is torn in the space, and the bag and the cloth are sucked into the void.
- If Deeppockets expires while there is material within the enchanted pockets, or a Dispel Magic is cast upon the enchanted garment, the wearer must make a saving throw versus spell. Failure indicates the material in those pockets has gone from extra-dimensional space to the Astral plane.
- If a spell caster detects a nearby astral viewing point into his plane, he may affect the viewers by a Dispel Magic. The chance of success is 50% plus [or minus] the difference between the caster’s level and the viewer’s level. If the Dispel succeeds, those viewers within 10 yards are sucked through the pool and into the caster’s plane.
- Plane Shift: Used to move an opponent to the Astral.
- Caught in an Ether Cyclone on the Ethereal Plane: Save versus magic or the party is blown to the Astral plane.
- Caught in a Sphere of Annihilation–Gate cataclysm that throws those within 18” into another random plane.
- The violet color on the prismatic spray/wall/sphere will transport to another random plane.
- Breaking a Staff of the Magi has a 50% chance of sending the mage to another random plane.
Unfortunately, there’s a lot of different, scattered, incomplete, and often contradictory resources on the Astral plane – it’s a lot of complicated information to reconcile if your party suddenly arrives!
I created a guide which should include a working summary of everything a DM will need to know to run a quick adventure on the Astral Plane. How do PCs get there? How do they move and fight? How do encounters work? Included also is a extended Random Encounter table created by consolidating monsters across resources (MM, FF, MM2).