Magic Wall Rune

This spell causes all particles that are contained in the surrounding air to quickly gather and contract until a solid wall is formed that covers one full square metre. The wall that is formed that way is impenetrable to any missiles or to light and no creature or character can walk through it. However, the wall will only last for a couple of seconds before it evaporates just as though it had never existed. It is always a good idea to have a magic wall rune or two in your backpack in case you are chased by a monster you just cannot hope to defeat.