“ It is possible to buy magical abilities. The process is very dangerous though, involving chemicals, rituals and surgery possibly leaving the aspiring mage insane, retarded or scarred for life.”
“ A cave with weapons sunken into the walls, blades sticking out of the floor and ceiling, and so on. Possibly, any weapon used in it could be torn out of the hand and sink into the stone.”
“ While it is within your purview to write long-spanning histories of your world, it is largely unnecessary. If you are running an RPG, do this instead: make a bullet point list of important events that affect the world today, and mysteries that people still don't know. Let these fuel your adventures.”