Princes of Amber
Shadows can be created by the Players and by the GM.
Mostly they are described purely in narrative terms, but there are a few characteristics of Shadows that have a mechanical effect in the rules.
These are called AXIOMS and there are three of them.
Axioms range from -3 to +3
Determines how easy it is to cast spells in the Shadow. See the MAGIC rules for details.
Shadow Earth has a Magic Axiom of -2, making it difficult to cast spells here.
Amber itself also has a Magic Axiom of -2.
This governs the general level of technology that works in the shadow.
0 is late medieval. Steam power would work if it had been invented but anything more technical like the use of electricity, plastics etc. would all fail. items brought in from other shadows transmute to local materials and cease to function.
-2 would be bronze age, worked iron goods would crumble here.
-3 would be pre-historic, zero technology, barely stone age. A wheel would work if you fashioned one out of stone or wood but won’t be something the locals understand.
Shadow Earth is +2 – computers and space shuttles
There are a few Shadows with higher Tech but these tend to be in specific fields (Bio-tech cyborgs, space-faring cultures that have occupied their own solar systems – no interstellar civilisations found so far).
This is really about how close to AMBER the Shadow is and how resistant it is to the powers of Logrus. It is harder to Shadow Walk where the Pattern is high and harder for Logrus users to use their Logrus-based powers.
In AMBER, the Patern Axiom is +3.
In Shadow Earth it is +1 because of the long time Corwin spent there.
In the Courts of Chaos the Pattern Axiom is -3.
In general minus numbers don’t seem to affect anything as the reverse weakening of Amberites in chaos does not happen – Amberites originally came from Chaos.
Some Advanced abilities may care about low Pattern Axioms.
Some Shadows might have special rules.
Perhaps there is a world where magic does not generally work but Necromancy (such as raising Zombies) is common-place. This might be indicated in the Magic Axiom as MAGIC-3 (Necromancy+2).
Perhaps there is a Shadows with similar TECH level to Earth except that it is still based on Steam (a Steam Punk “modern” victorian age?). This might be indicated as TECH+2 (Steam replacing petrol)
Notes about Shadows and Shadow Walking
Shadows gain a kind of “gravity pull” based on how frequently they are visited by “real” creatures – particularly by those with the blood of Amber. This makes it really hard for somebody to Shadow Walk to a place that is very, very close without being pulled to the specific Shadow instead.
So trying to get to a parallel Earth that is exactly the same except for some tiny detail, will instead get you to the Shadow Earth that Corwin and Florimel have spent a lot of time in.
Limits on Chaos
At first glance it might seem as though Logrus Shadow Walk is exactly the same as Pattern Shadow Walk. However, the Pattern has had such a profound effect on the nature of the multiverse that Logrus Shadow Walk becomes increasingly difficult in places with a high Pattern Axiom and completely ineffective in a shadow with Pattern+3.