Efficiency

Level 4 of the Dungeon

Level 5 of the Dungeon
(12, 12, D:5)
  a +0 short sword

Level 6 of the Dungeon
(0, 0, D:6)
  a +0 leather armour
(4, -1, D:6)
  a +0 ring mail
(6, 0, D:6)
  an adder corpse