It's a trap

Item class has only 12 functions left to complete. Some items can be trapped and for a long time traps gave me constant headache in the way I was trying to implement them. The confusion was caused by the type of traps. Some of them are actual objects hidden on ground, while others are a part of another object. Also, I had difficulties to understand how to implement the effects of traps. If I can handle traps then the entire object system is much closer to be complete, because traps are one of the unfinished parts that affect several object types.