EGO

Some items have "ego". This means that they have a certain amount of willpower of their own. This willpower must be overcome by the player in order for the player to be able to use the item.

The player's

( level + 2*wisdom + intelligence + charisma ) * ( .5 + ( % of max HP ) / 2 )

must be greater than the item's ego in order for the player to use the item.

Example:

Item has an ego of 60.

Players stats are: lev=25, wis=14, int=16, cha=9, hp=20, max hp=40

Max ego the player can overcome is (25 + 2*14 + 16 + 9 ) * (20/40) = 39.

Thus the player would not be able to use the item. If the player was all healed, however, she would have been able to overcome the object.