You defeated 50 enemies with a single (swingable) sword.
You forged a runic item.
You discovered all levels in the Dungeon of Doom.
You discovered 5 levels in the Dungeon of Doom.
You visited all 9 floors in the dungeon.
You defeated the Balrog as the Wizard.
You collected 12 pieces of Mithril ore as the Dwarf Warrior.
You performed 20 stealth kills as the Halfling Rogue.
You collected 72 arrows as the Elf Archer.
You crafted a magic shield as the Human Warrior.
You didn't fire your bow until you reached the Living Quarters.
You picked a lock on a door or a chest.
You killed 100 Creeps.
You scored 250 kills.
You defeated the Visitor Queen.
You found another repeater crossbow.
You visited all 11 floors in the Mining Colony.
You climbed down a chasm.
You explored all 10 levels of the Dark Ritual.
You reached the court of the Crimson King.
You defeated a Wraith.
You cast a spell to reveal a treasure.
You recharged a spent magic staff.
You found the Ritual Location.
You collected 48 arrows.
You put a skeleton permanently to rest.
You crafted a necklace of Orc teeth.
You slayed a real Dragon!
You discovered 7 levels in a hard game after starting with no equipment.
You killed a Boss with a pistol or musket.