Here is the full list of all 35 Avernum: Escape From the Pit achievements.
Complete all three game-winning quests in Avernum and never set the difficulty below Normal.
Complete all three game-winning quests in Avernum and never set the difficulty below Hard.
Complete all three game-winning quests in Avernum and never set the difficulty below Torment.
Deliver harsh vengeance to the cruel tyrant who sent the Avernites into the underworld.
Learn 18 priest spells at level 3.
Destroy the demon Grah-Hoth, making Avernum safe from his menace at last.
Learn 18 mage spells at level 3.
Discover a route back to the surface world. There must be one somewhere.
Have fifty potions made.
Dig up 40 caches.
Find the secret at the bottom of Lost Bahssikava.
Avernum has five dragons. See if you can whittle that down a bit.
Dig up 5 caches.
Get a dread curse. Then cure it.
Learn 6 mage spells at level 3.
Meet the Archmage Erika.
Purge a certain powerful demon from the Tower of Magi. Phew. Hope they stay out of trouble in the future.
Learn 6 priest spells at level 3.
Join the Scimitar.
Reform a legendary blade from Avernum's past.
Steal the treasure from Gremlin's Gold.
Learn a priest spell at level 3.
Sss-Thsss will trouble Avernum no longer.
Have ten potions made.
Learn a mage spell at level 3.
Find something that lets you fly.
Discover 50 locations of interest.
Slay 1000 foes.
Enter the Castle at last.
The mayor of Formello lost something of great value. Recover it.
Discover 10 locations of interest.
Purge a nefarious infiltrator from Silvar's sewers.
Slay 100 foes.
Open a secret door.
Escape the tunnels under Fort Avernum.