Remove magical barrier [846]
----------------------------
Usage:  USE 846 <direction> [aura]

Required aura:  one to four points, as given
Required item:
Time to cast:   seven days

Attempt to remove a magical barrier from the location in the
given direction.  If direction "0" is given, a barrier over
the current location will be removed.

The chance that the barrier will be successfully removed is
proportional to the aura invested in the attempt:

	aura	chance of success
	----	-----------------
	 1             10%
	 2             25%
	 3	       50%
	 4	       75%