Doors that are locked can either be smashed down by attacking the door or by using keys which can be found throughout the game. Pits can be doorways to new areas of the map too, but be careful, for you could fall down into a pit full of ghosts or dragons and not be able to get back out. Are a common occurrence in Crossfire. Some firewalls can be destroyed others cannot. These odd items will change the direction of any item flying over them, such as missile weapons and spells.
Some items are perishable.
So be careful not to destroy valuable items. There are many, many different types of books and scrolls out there. These magical weapons can do many things - improve stats, have lower weight, higher damage, etc. The method for creation and further improvement was changed in version 0.91.7. Both methods are listed here, because it is possible to enable the old version on a server by server basis.