40 achievements in total:

• 10 combat-related achievements
  
• 3 for class specializations (core+advanced)
  • learn all skills of a skill tree - 1/3
• 3 for buying and selling equipment to spend and earn Arcadian
  
• 11 relating to Overworld management
  • Contract - 2/11
    
  • Rec Lefty - 1/11 (contract-related)
    
  • Recruitment - 2/11
    
  • Promote units - 2/11
    
  • Dismiss a soldier - 1/11
    
  • CMD usage - 2/11
    
  • Read all Chatter - 1/11
• 12 story-related achievements
  • 5/12 dependent on choice
• 1 completion achievement

Blinded by Science
Blind a unit


No Think, Only Smash
Inflict Rage on a unit


Use the Inquisitor's Baiting Strike for a 75% chance (at MAX) to inflict Rage on an enemy unit.

Soldier of Love
Charm a unit


Use the Ronin's Possessing Spirit for a guaranteed Charm on an enemy unit.

One Way Ticket to Lethe
Elemental Stacking - Triggered elemental bonus damage against a target


A couple of easy bonuses: Noxious + Fire -or- Wet + Lightning

Untouchable
Win 10 battles without a single unit knocked unconscious


Watch Your Step
Trigger a Trap 20 times


You can step on your own flame tiles from Fire Wall for this achievement.

Two for One Deal
Kill 2 units with a single attack



Obtained naturally especially if you do all possible contracts alongside the story.

For A Better World
Killed 20 Monster units


For Queen and Country
Killed 30 Lucretian units


For Sword and Crown
Killed 30 Dantalion units

Jack of all Trades
Learn all skills on a single skill tree in one playthrough


This is best done near the end of the game. I got it by spending at least one point on each of the Cavalier's possible skills. I tried the same thing with an Apothecary but it didn't pop.

A Well Rounded Military
Get all Core Class specializations across troops


Military Mastery
Get all Advanced Class specializations across troops


With regards to these 2 achievements:

• Core = Basic Classes (Cavalier, Apothecary, Etc)
  
• Advanced = their Promotions

There are 9 Core Specializations:

• Cavalier = One-Handed / Two-Handed
  
• Apothecary = Field Medic / Corrosive Concoctions
  
• Warmancer = Path of Flame / Ice / Lightning
  
• Ranger = Bow Mastery / Crossbow Mastery

There are 16 Advanced Specializations (4 Core Classes * 2 Promotions * 2 Specializations):

• Cavalier
  • Inquisitor = Holy Reckoning / Aura of Light
    
  • Ronin = Wandering Soul / Trance Arts
• Apothecary
  • Monk = Furious Blows / Arcane Energies
    
  • Shaman = Cosmic Overseer / Darker Paths
• Warmancer
  • Druid = Nature's Harmony / Manipulate Earth
    
  • Sorcerer = Wild Magic / Touch of Death
• Ranger
  • Hunter = Death from Above / Guerilla Tactics
    
  • Reaver = Dagger Arts / Hired Assassin

To get these achievements, you need at least 1 of each Specialization concurrently. You'll know that a unit is specialized if they have the Specialization text under their respective Class/JobYou can complete both achievements as soon as level 19 since you only need to spend as little as 1 skill point in the Advanced Classes to pick a specialization. This means you'll need at least 16 differently specialized recruits (Uniques included) to earn Military Mastery.

Mercenary for Hire
Completed 5 tavern contracts in a single playthrough


Tavern → Chatter

Sword of the People
Completed 10 tavern contracts in a single playthrough


Of Red Pandas and Trash Pandas
Recruit Lefty


In Chapter 3, there will be a contract related to Lefty. Upon completing this Contract's battle, Lefty automatically joins after a heartwarming cutscene. There's also a Contract related to Poncho in Chapter 1. I'm not sure if this is required, but to be on the safe side I recommend just completing all available contracts per chapter.

A Few Good Men
Recruited 5 units in a single playthrough


We're Going to Need a Bigger Army
Recruited 15 units in a single playthrough



Medal of Honor
Promote your first unit


Gotta Catch Them All
Promote units to all advanced job classes


Out With the Old
Dismissed a soldier



Book Worm
Read all chatter in a single playthrough


Tavern → Chatter

Created In Our Image
Respec any unique with CMD Points


Recruiter → CMD

To The Victor Go the Spoils
Spent a total of 6 CMD Points


Despite the description, I got this after spending points 6 times as opposed to 6 points.

Before you continue, please note that choice-related achievements can be obtained in 1-run by simply saving and reloading prior to the choice and selecting the alternative. Save before each event/battle/cutscene.

The following achievements are story-related, grouped by chapter, in chronological order:


A Kingdom Burning
Chapter 0 Complete




Dances with Raccoons
Recruit Poncho


Tirgan's Favorite
Chapter 1 Mission 45 - Vashti Discovery Choose Lucretia


Friendship is Magic
Chapter 1 Mission 45 - Vashti Discovery Choose Eda


Save Those You Can Save
Claude Lives


The Desperate and Downtrodden
Chapter 1 Complete




Children of the Moon
Chapter 2 Mission 88 - The Fool


Principalities and Powers
Chapter 2 Complete




Riddel's Redemption
Chapter 3 Mission 206 - Lundum Hills Recruit Riddel


Breaking the Cycle of Violence
Chapter 3 Mission 206 - Lundum Hills Don't Recruit Riddel


Execution of Justice
Chapter 3 Mission 212 - Wulffs Execution


And Death Itself Shall Die
Chapter 3 Complete

Crowning a New Ruler
Collected all Achievements