Full list of all 46 Dauntless achievements worth 2,000 gamerscore. It takes around 150-200 hours to unlock all of the achievements in the base game on Xbox One.
The base game contains 10 achievements worth 1,000 Gamerscore, and there are 13 DLC packs containing 36 achievements worth 1,000 Gamerscore.
Defeat a Behemoth with Every Part Broken
Craft a Weapon from Behemoth Parts
Cook an Epic Cell with the Middleman
Complete 100 Perfect Dodges
Slay a Frostback Pangar
Defeat Shrowd and Rezakiri
Reach Mastery Slayer Level 40
Reach Max Level on a Hunt Pass
Reach Mastery Level 10 in 7 weapons
Complete any Mastery Card
Emerge Victorious from a Trial
Build a Loadout with 6 Different +6 Perks
Craft any Blaze Aether Strikers
Hit a Behemoth with Titan's Crash while Tempest Form and Karma Breaker Effects are Active
Defeat Tempestborne Stormclaw with a War Pike
Complete an Escalation
Craft and Bond a Legendary Weapon
Slay Malkarion with a Terra Weapon
Craft a Weapon or Piece of Armour from Torgadoro Parts
Reach Level 25 in any Escalation
Slay Flameborn Rezakiri
Slay Thrax with the Hammer, Sword, and Chain Blades
Make 25 Discoveries
Slay a Sporestruck Charrogg and a Sporestruck Embermane with the Parasitic Perk Equipped
Craft an Exotic Weapon or Armour Piece
Slay Agarus with a Shock Weapon
Reforge a Weapon Skill
Successfully Complete 10 Island Events in the Hunting Grounds
Equip a Full Set of Power Surged Gear
Unlock Milestone V on the Slayer's Path
Unlock Milestone XII on the Slayer's Path
Defeat Malkarion, Torgadoro, Thrax, Agarus, Urska, and The Chronovore
Slay Kaltauga, Scourge of the Skaldish Highlands
Discover a Rumour in the Shattered Isles
Wound an Umbral Behemoth with a Radiant War Pike
Craft a Piece of Timeweave Armour
Defeat The Chronovore
Craft and Equip an Omnicell
Complete a Heroic Escalation
Slay Thunderdeep Drask
Craft Repeaters of Every Element
Slay Five Behemoths on The Blazeworks
Defeat Phaelanx
Do 100,000 Total Damage with the Revenant Omnicell
Complete 4 Seasonal Challenges
Slay Bloodshot Shrowd