Runes: size & power
The representative size of an enchanted rune has little to do with the power of that particular rune itself. The shape and form of the rune are what captures - focuses - contains the power therein. As long as the rune is clearly & properly inscribed - etched - depicted by an adept of the Rune-weaving craft, the power is imbued. It is the skill and power of the adept that informs the power of the enchanted rune. The physical size of the rune (be it major or minor) is strictly a style choice of the adept performing the ritual.
The finest swords forged in Mogadur, city of the Greater Noble House Kotar, masters of Construct, often feature a minor rune or two etched into the blade or tang, imbuing the blade with some mystical quality.
I'm still a bit confused. When you talk about runes, it almost sounds like you are talking about two different things.
Is a "rune" a etching (like shown for the Greater Houses/Emperor), an enchantment onto an object, or a physical object such as a gem?
A rune is magical sign or letter. It can be etched or inscribed on a variety of surfaces and objects. Anyone with the materials can depict runes - just as can be done with letters. Only adepts of the mystical art of Rune-weaving can imbue a rune with power - making it a magical rune.
A Rune-weaver placing runes upon an item (weapon, wall, gem, scroll, etc.) and imbuing them with power, in effect, creates a magic item (A cool example of a historical runic-weapon would be the Spearhead of Kovel).
Imperial Roads are a prime example of "runic" structures. Constructed by House Kotar, warded against wear and the elements by House Morana, and Imperial Rune-weavers etching the appropriate runes into the very stones of the road and imbuing the magical powers of all three into a permanent state to create roads that are maintained without need of constant repair.
The Runes Major are most commonly seen as heraldic symbols for the Greater Noble Houses which are the acknowledged masters of the particular discipline displayed. The rune does NOT belong to the House. Rather, it represents a magical discipline. The Greater Noble Houses subtly attempt to lay claim to their particular magical discipline by incorporating the rune into their heraldry.
A rune can simply be a drawn symbol. Or it can contain, harness or release magical power if imbued by a Rune-weaver. Etched or inscribed upon an object by a Rune-weaver, it imbues, or enchants, the object with a magical power based upon the rune inscribed.
I think I understand a bit better now.
Do all of the minor runes represent minor disciplines like how the major runes work or do the runes represent specific spells/enchantments that might fall under a specific discipline?
If one had a codex of all major and minor rune symbols, would you know exactly which enchantment that item held?
Would all magic from a noble house be represented by the same rune (if the magic all fell within the same discipline)?
Would this be how the road was built:
Step 1) House Kotar cut the stones, laid the road surface, and then cast a spell to ??
Step 2) House Morana cast a spell to protect the surface against the elements/weather
Step 3) Imperial Rune-weavers etch the runes of Kotar and Morana disciplines onto the surface and made the magic permanent
Are all magical items (during Age of Gallidon) made permanent by an Imperial Rune Weaver? So effectively, all magical items were owned or somehow came through the Emperor. Would this mean you wouldn't commonly find magical swords and armor at the bazaars?
I'm trying to get a feel of whether its a high-magic or a low-magic setting and it feels like a low-magic setting since only the rune-weavers could actually make the magics permanent and there were only 3 of them at any given time working for the Emperor.
Few boundaries are set for Runes Minor - they may represent specific effects-enchantments-spells or possibly a new discipline just being discovered and developed.
If one had a codex and the skill (Gift) to truly recognize the individual runes, one could guess with certitude what enchantment the item held. Uncertainty could arise from the arrangement of the runes in relationship to each other or the placement of the runes on the item, but the runes themselves could be identified with such a codex. An adept of Rune-weaving can typically make such an identification.
The Runes Major are typically reserved for the most powerful of spells within its discipline. Spells or effects of lesser magnitude are typically represented by Runes Minor.
Step 1) House Kotar cut and arranged the stones, laying the path and physical structure of the road itself using their masonry and architectural skills enhanced by the mystical art of Constructs.
Step 2) House Morana created a Ward to protect the physical structure of the road against the elements/wear/time.
Step 3) Imperial Rune-weavers etched the runes of Constructs, Warding and the Emperor's Rune (Rune-weaving) onto stones of the road and made the magic permanent.
While there were rarely more than fifty Imperial Rune-weavers at any time (with three being Rune-weaving Masters), there are many individuals who have some grasp of the art of Rune-weaving. These non-Imperial Rune-weavers access and utilize Runes Minor with varying degrees of success. Attempts to use Runes Major by these individuals typically meet with tragic results. Runes Major were only known to be successfully used by Imperial Rune-weavers.
Minor enchantments on swords and armor, while unusual, are not unknown. Most cities (Mogadur is the most famed) have at least a few individuals familiar with the basics of Rune-weaving. Any item imbued with a powerful enchantment most likely came from the hands of an Imperial Rune-weaver or would be a relic from the Age of Disorder.