Runecrafting

Requirements
The buildings that can be runcrafted: The building must be Level 10 (using a Hobbit Building Crew or Master Builder item) to runecraft, and it costs 0 runes and 0 seconds to runecraft to ★1
 * Vault
 * Keep
 * Muster Field
 * Barracks
 * House
 * Wall
 * All 4 res fields

The time increases for ★2 and ★3, but no Forge Runes are required.

Some buildings require other buildings to be ★1 to upgrade them. Some will require 2 or 3 other buildings to be crafted to specific levels.

Generally you will need these res fields at level 10 and runecrafted to build advanced runecrafted buildings: To runecraft a building to level ★4, you need 1650 Forge Runes, which can be won as prizes, in mystery boxes, or by defeating the last "boss" city on a campaign map. Runes are not guaranteed to be dropped after a campaign "boss" win.
 * Ore Vein
 * Arboretum/Lumber Mill
 * Quarry

The time and resources required increases for ★5 and ★6, but once again, no runes are required.

To runecraft a building to level ★7, you need 2570 Ascension runes, which can be obtained by trading Forge runes in your sages tower (4200 for 1000, or 40000 for 10000).

Level ★10 Rrequires Master Runes, which can be traded for with either Forge Runes or Ascension Runes in your sage tower. Many more Forge Runes are needed to get Master Runes than Ascension Runes.

All of these runes can also be won in certain chests that are purchased or won from Galadriel's Token chance.