Please let me know what you think of this magic item that I'm planning on dropping in my current Mystara campaign using BECMI rules:
Kagyar’s Instant Forge-tress
by Michael HanelineThis engraved stone cube is 4 inches on a side. When activated, it grows to form a 2-story dwarven “tower” that is 25 feet square and 20 feet high with arrow slits on all sides with a machicolated battlement atop it. It has iron walls that extend 10 feet into the ground. The forge-tress has a small door that opens only at the command of the owner of the forge-tress - even knock spells can’t open the door. On the first story is a strange 10ft. cubic device with an opening into which building supplies can be deposited, lost forever. If architectural blueprints for a building that fits in a 40x40x40ft. area are also “fed” to the device after sufficient raw material to build said architecture, the building will materialize, perfectly built, over the course of 24 hours in a desired location within 50 ft of the forge-tress; this new structure is not considered part of the forge-tress. On the second story is a high-quality forge that provides a -1 bonus to any checks made to use it. When used to make magic items, the forge improves the chance of success by 10%.
The enchanted iron walls are unaffected by normal weapons other than siege weapons. The forge-tress can absorb 200 points of damage before collapsing.
The forge-tress gradually transforms from cube to building or back again over the course of 5 minutes on command, with the door facing the device’s owner. It will not transform back into the cube if anyone is inside it. All non-living items inside are placed in stasis. If transformed into a forge-tress in a cave that is too small to hold it, it will push away any rock that is not harder than feldspar. Otherwise, the structure takes 10d10 damage and then transforms back into a cube.
