Welcome to Mage, where you may need multiple books for all the realms. One of the best resources is the good old Beyond the
Barriers: The Book of Worlds (BtB:BoW), which actually had some access rules, but you also need the M20 Core rulebook. Spreading the look, the W20 version of the Umbra: the Velvet shadow (W20 Umbra) from the Werewolf line can help with some place-specific mechanics and the inhabitants' statistics, and for one Area we need to look to Changeling.
Methods of Travel
M20 covers most of the typical travel methods into the realms mostly in fluff. Book of Worlds provides more fluff and a simpler map. It also provides a good chunk of systems for each of the zones, so will be your best reference. Of particular note is the spreadsheet below from the Book of Worlds.1
Travel Methods
Place |
Means of Travel and Navigation |
Periphery |
Awareness, Dream, Rank One Spheres, Auspex 2 |
Astral Travel |
Mind 4or5, Auspex 5, Clairvoyance 5, Gifts; navigate by Perception + Occult |
Stepping Sideways |
Spirit 3 (4 to bring others), Gifts (innate to Garou); navigate by Perception + Enigmas (shapeshifters) or Wits + Cosmology (mages) |
High Umbra |
Astral travel, stepping sideways (Vulgate only); navigate by Perception + Occult, or Intelligence + Occult (Epiphamies) |
Middle Umbra |
Stepping sideways, astral travel |
Low Umbra |
Entropy 4/Life 2/Spirit 3; navigate by Wits + Occult |
Realms |
Portals, gates or Anchorheads |
Paradox Realm |
Find (Perception + Spirit Lore), step through |
Maya |
Mind 1/Spirit 1, or fae enchantment to see; sleep, Mind 3 to visit (only Dreamspeakers can step sideways); navigate by Wits + Enigmas |
Hollow World |
No magick necessary |
Horizon |
Spirit 5, Mind 5, or Willpower roll (10 successes out, 15 successes in) |
Anchorhead and Aetherian Reaches |
Willpower roll (5 successes, difficulty 8) |
Deep Umbra |
Spirit 5, Mind 5, Life 3, or life-support device for long survival; navigate by Perception + Cosmology. |
World to World |
High Umbra/Dream Zone to other: Willpower roll (difficulty 8); Middle to High Umbra: climb Pattern Web (Dexterity + Athletics or Cosmology); Low to any: Entropy 5/Spirit 4, Entropy 5/Mind 5 for an Astral traveler, or Argos 4; Realm to Realm: Portals and gates. |
Note that beyond Spirit 3+, Mind 4/5 is a way to access many places (or their Astral version), and that hostile places like Low Umbra require Entropy and Life (or being a Werebeing) to not die.
Also, note that Maya is the fringes around The Dreaming and the most accessible to any being.
Umbra is easy
The Penumbra and then the Umbra is easy: Spirit magick allows to directly go there (Stepping Sideways) or open a gateway to this spirit realm, Mind magick allows Astral Travel, which opens to the Astral side of these realms. Either way, once you are in the Penumbra, getting to the other areas is mostly traveling up and surviving the trip.
Werewolves say the Umbra separates basically into Near Umbra and Deep Umbra, without a proper corresponding match to the high/middle/low of mages. Only Dark Umbra corresponds neatly to the Low Umbra and Astral Umbra matches the Astral Realms. Oh, and they know the deep umbra... and somewhat manage to handle some of it.
- The Penumbra is a truly shared place between Mages and all other splats that have access.2
- Low to High Umbra are less shared, as many other splats only get partial access. Werewolves are among those with the best access here.3
- Astral Umbra is very linked to the other Umbra-areas, but you only can access it via Astral Travel. Some of the Astral Realms are also accessible via other routes (including dying!), especially the afterlives. 4
- Middle Umbra has a few subrules and contains most of the Realms. 5
- Lower Umbra likewise has subrules and contains some of the less... pleasant Realms. 6
- Deep Umbra is taxing for mages and will kill you. Even if you can go there, you don't want to. If you have to, try to get a Werewolf guide or an Anchor. That's your only way back. 7
The Digital Web is different
While most realms are accessed with Spirit or Mind, the Digital Web is usually accessed with the sphere of DATA. 8
Horizon Realms
These are the manifestations of the spheres and their associated planets. Those Shard Realms can be accessed directly with their sphere at times (at least Doissetep and Neptune used to be before an event). 9
Dreaming is unavailable
Any of the Dreamings are unavailable to Mages, because mages are not Changelings and have no glamour score. Without a glamour score, it's virtually impossible to access there and most Magi are wellsprings of Banality anyway. As a result, the three layers of the Dreaming are exclusive for Changelings. Maybe, if enchanted by a fae and of low banality, then a mage might be lead into the Near Dreaming, but they can't access it on their own. Part of this is discussed in the chapter on Maya.10
Why is it inaccessible? The typical traditionalist mage has a Banality rating of 6, the typical Technocrat has a banality of 10. Only truly dreaming mages (Cult of Extacy) have a lower banality, and even then only down to about 3, which is an exceptional Dreamer in Changeling terms - someone that produces Glamour. But even a Banality 3 character still goes quite easily bonkers in the Dreaming, if a Changeling leads them there. That is because they can't have a glamour stat to balance out their Banality and get into the Glamour side of the scale. So, most Mages will face the following effects:
5 Banality: Unable to withstand the sights around her, the
character lashes out at anything within striking range while
she battles her own mind and understanding of the mundane.
6 Banality: The character actively refuses to believe
anything she sees and is convinced that she has lost her mind.
7 Banality: The concept of the Dreaming overwhelms the
character and he can do nothing but stare while lost in thought
and contemplation.
8 Banality: Nothing around her makes sense anymore. She
attacks anything and everything that surrounds her so that she
may go back to her own world again.
9 Banality: The character’s mind gives way to unconsciousness
rather than forcing her to confront the world before her.
10 Banality: This character cannot enter the Dreaming.
Her very presence is an affront to it.11
And as their net banality is 3 or above, they can't even remember having been there in the first place the moment they wake up:
3+ Banality: While the character considers the notion
of the Dreaming ridiculous, she occasionally suffers intense
dreams or flashbacks of events that took place during her visit.11
1 - M20 p.85-89, BtB:BoW p.14 & 18, BtB:BoW pp.182, Spreadsheed: BtB:BoW p.186. Specific Realm Mechanics: BtB:BoW pp.187.
2 - M20 pp.89, BtB:BoW p.24, W20 p.309, W20 Umbra pp.37.
3 - M20 pp.91, BtB:BoW pp.50.
4 - M20 pp.94, BtB:BoW pp.26, W20 Umbra pp.96.
5 - M20 pp.97, BtB:BoW pp.53, W20 Umbra pp.99.
6 - M20 pp.99, BtB:BoW pp.34. (astral afterlives), BtB:BoW pp.71 (true lower umbra)
7 - M20 p.114, BtB:BoW pp.159, W20 Umbra pp.103.
8 - See M20 pp.103 & pp.463, BtB:BoW p.52 for the Digital Web and M20 pp.534 for Data.
9 - M20.pp.109, BtB:BoW pp.32, BtB:BoW pp.101. & pp.137
10 - M20 pp.101, BtB:BoW p.51/52 & pp.77. Note that Maya is distinctly different from the Dreaming. More about the Dreaming: C20 pp.300.
11 - C20 pp.303.