Squire
Complete the first level of a play session, without taking any damage.

--- w/ Apprentice?: No, LOCKED

This will most likely be unlocked during the tutorial at the very start of the game.


Adventurer
Complete the first 3 levels of a play session, without taking any damage.

--- w/ Apprentice?: No, LOCKED

It's up to you, how difficult this'll turn out to be.
Just go for the Jack of Skulls or the Queen of Dust, and put as many non-gambling & non-combat encounters in your deck, as possible.

Early on available recommendations are, among others:

• Local Peasant
  
• Noble Trader
  
• The Lonely Bard
  
• Angry Guild Master
  
• Helpful Priest
  
• Loan
  
• Marketplace
  
• Trading Post
  
• Food Wagon
  
• Mister Lionel
  
• The Maiden
  
• Twisted Canyon
  
• ... and so fourth

Very Lucky
Get 15 'Success' or 'Huge Success' chance cards in a single session.

--- w/ Apprentice?: No, LOCKED

Very Unlucky
Get 12 'Failure' or 'Huge Failure' chance cards in a single session.

--- w/ Apprentice?: No, LOCKED

Probably the easiest way to do these, is to play in endless mode.
But you may also put the "River" encounter in your deck and use it, until the achievements pop up. The River route is kinda difficult to pull off, though, because you'd need a lot of food.

Master Combatant
Complete 3 combats in a single run, without taking any damage.

--- w/ Apprentice?: No, LOCKED

This achievement is easily earned, especially earlier on, when you are fighting small groups of dust.
Tip: Use a shield, so that you can counter enemy attacks.


Very Brave or Very Stupid
Enter a combat with less than 5 health remaining.

--- w/ Apprentice?: No, LOCKED

Close Shave
Win a combat with less than 5 health remaining.

--- w/ Apprentice?: No, LOCKED

Go against the Jack of Dust. Clear the entire stage, apart from the boss. Just hop between the cards until you're out of food and close to 5 health. Upon hopping on the Jack of Dust card, you'll lose another stack of HP, before the fight starts!

The Jack of Dust should then easily be doable for you without taking damage, especially with a shield equipped.


Slayer
Perform 2 prone attacks in a row.

--- w/ Apprentice?: No, LOCKED

I'll just redirect you to this guide:
https://steamproxy.net/sharedfiles/filedetails/?id=761133597


Master of Traps
Bash 5 enemies into traps in a single session.

--- w/ Apprentice?: No, LOCKED

"Bashing" refers to the stun attack. You can push one and the same enemy into the trap several times.
Search yourself a map with traps hidden in bushes. For example:



Hunter
Land the killing blow on 10 enemies with a trap.

--- w/ Apprentice?: No, LOCKED

I recommend doing this achievement in the "Dead King's Hall" encounter, because of the fact that it is riddled with traps.


Quick Reflexes
Reflect 100 projectiles over multiple play sessions.

--- w/ Apprentice?: No, LOCKED

Ninja
Kill an enemy with their own reflected projectile.

--- w/ Apprentice?: No, LOCKED

Well, keep reflecting your enemy's projectiles with your shield. These two will unlock, eventually.


Champion
Kill one of each monster type in a single session.

--- w/ Apprentice?: No, LOCKED

This requires:

• Dust | Bandit
  
• Skulls | Skeleton
  
• Plague | Ratman
  
• Scales | Lizardman
  
• Lava Golem
  
• Mage
  
• Lich
  
• Minotaur (White one works perfectly fine for this)

This achevement is somewhat hard, because you must kill one of each type of monster.
I recommend using endless mode to get this one. It may take a while, but you'll almost definitely get all of them before level 30, which in return is needed for another achievement.

Release the Lich!
Complete the Lich encounter.

--- w/ Apprentice?: Yes, unlockable

Defeat the Jack of Scales, complete the "Dark Ritual" encounter and you'll unlock the "The Lich" encounter. This can not be removed from your encounter deck, until you've completed it. So don't mind this achievement, it will pop up by itself.


Release the Lava Golems!
Complete the Fire in the Deep encounter.

--- w/ Apprentice?: Yes, unlockable

Defeat the Queen of Plague and you'll unlock the "Fire in the Deep" encounter. This can not be removed from your encounter deck, until you've completed it. So don't mind this achievement, it will pop up by itself.


Release the Mages!
Complete the Mages encounter.

--- w/ Apprentice?: Yes, unlockable

The Mages will be unlocked during the "The White Council" story-line.
All requirements of these encounters are pretty straight-forward, so no further explanations at this point.


Release the Minotaur!
Complete the Minotaur encounter.

--- w/ Apprentice?: Yes, unlockable

The Minotaur is, (not) suprisingly part of the "The White Minotaur" story-line.
This includes the following encounters:

• The Song of the White Minotaur
  
• Hunting the Huntsman
  
• The Mug and Barrel
  
• Tracks in Town
  
• The Labyrinth
  
  • This one will unlock you the "Release the Minotaur!" achievement
• The White Minotaur
  
  • This one will unlock you the "Great Hunter" achievement

All requirements of these encounters are pretty straight-forward, so no further explanations at this point.


Dungeon Master
Defeat the Dealer.

--- w/ Apprentice?: No, LOCKED

Well, defeat the Final Boss.
Good luck.


Humbled
Complete all 6 Charity encounters.

--- w/ Apprentice?: Yes, unlockable

After defeating the Jack of Skulls, you'll receive the card "Helpful Priest". Finish this encounter, and you'll be given the first "Charity". For each cleared Charity, you'll receive the next until "Charity VI".

• Encounter 1-3 require at least 1 food
  
• Encounter 4-5 require at least 5
  
• Encounter 6 requires at least 30!
  
  
• You might want to give more than the minimum though, because more food = better chances at success, which is the requirement for unlocking the next encounter.

Corrupted
Complete all 6 Demon Trader encounters.

--- w/ Apprentice?: Yes, unlockable

After defeating the Queen of Dust, you'll receive the card "Battle at Brooktop". Finish this encounter, and you'll be given the "The Altar" encounter, after which you'll unlock the first "Demon Trader". For each cleared Demon Trader, you'll receive the next until "Demon Trader VI".

• Encounter 1 requires you to give up 1 Blessing
  
• Encounter 2-5 require you to give up 2
  
• Encounter 6 requires you to give up 3

Drained
Complete all 6 Blood Auction encounters.

--- w/ Apprentice?: Yes, unlockable

After defeating the King of Dust, you'll receive the card "Stranger in the Shadows". Finish this encounter, and you'll be given the first "Blood Auction". For each cleared Blood Auction, you'll receive the next until "Blood Auction VI".

• Encounter 1-6 all require you to bid at least 60! Health
  
  
• You might want to give more than the minimum though, because more Health = better chances at success, which is the requirement for unlocking the next encounter.

Pure Enlightenment
Possess 10 Blessings at once.

--- w/ Apprentice?: No, LOCKED

Wretched Soul
Possess 10 Curses at once.

--- w/ Apprentice?: No, LOCKED

The fastest way to do this, is to play the King of Skulls 'campaign'.
This campaign comes with 5 "The Hanged Man" encounter, which all give you 1 blessing AND 1 curse, each.
The curses can now easily be completed by single "Cursed Treasure" encounter, which gives you another 5 curses. I've tried it 3 times, and got this encounter in all tries.

Collect 5 further blessings requires a few more encounters, but it's also quite doable.
Remember, that you can buy blessings at the "Call for the Priest" shop, for 75 gold each.

Encounter cards, which CAN grant you blessings, include:



Juggernaut
Possess 150 or more health.

--- w/ Apprentice?: No, LOCKED

This achievement would be hard by itself, but by using endless mode as the Lion Pride class, it can be easily obtained after a peroid of combat.


Well Supplied
Possess 120 or more food.

--- w/ Apprentice?: No, LOCKED

This achievement is very hard, as food is consumed all the time and at times is very expensive. However, by using the wheel of gods encounter, one can get a lot of food.


Wealthy Lord
Possess 200 or more gold.

--- w/ Apprentice?: No, LOCKED

Already upon defeating the first boss, the Jack of Dust, you'll be given the "Mercenary Contract" equipment card. It's an artifact, which can be activated once per battle, and rewards you with a few coins for each successful hit on a foe. With that, and one encounter with "The Maiden", which I asked for gold, I even managed to get this achievement on the second boss, the "Jack of Skull".
But you might also play endless mode, and get this over time.

Combat Ready
Have at least 1 of each type of equipment in your inventory.

--- w/ Apprentice?: No, LOCKED

This requires everything but a blessing, or in other words:

• Weapon
  
• Shield
  
• Armour
  
• Helmet
  
• Gloves
  
• Ring
  
• Artifact

Before attempting this achievement, make sure that you have at least one of each of the equipment type of cards in your deck.
You might start with a DLC class, to have a helmet from the get-go. You can almost guaranteed buy the "Hag's Wraps" gloves from the traveling mage, if you don't have a glove equipment card, yet.
Shops have different items, each time you visit them. Even within the same session.

Tip: You can do this in endless mode.


Bling
Have 10 rings in your inventory at once.

--- w/ Apprentice?: No, LOCKED

I easily got this by ONLY putting rings in my equipment deck and playing the Jack of Scales.
Every single equipment draw encounter guaranteed a ring, "The Lover" even guaranteed 2.
The rest can be bought at the shops.
But you might as well go for this achievement in the endless mode.


Arch-Mage
Equip all the Mage items at once.

--- w/ Apprentice?: No, LOCKED

This requires:

• Mage's Mask
  
• Mage Gloves
  
• Mage Strike

You unlock all 3 equipment cards by completing the "The White Council" story-line.


King of the Undead
Equip all the Skeleton King items at once.

--- w/ Apprentice?: No, LOCKED

This requires:

• Skeleton King Sword
  
• Skeleton King Shield
  
• Skeleton King Helm

You unlock all 3 equipment cards by defeating the King of Skulls.


Dragon Slayer
Equip all the Dragon Relic items at once.

--- w/ Apprentice?: No, LOCKED

This requires:

• Dragon Tongue (sword)
  
• Dragon Shield
  
• Dragon Armour
  
• Dragon Helm
  
• Dragon Claws
  
• Dragon Breath
  
• Dragon Ring

In order to unlock the Dragon cards, you need to:

• Defeat the Queen of Scales
  
• Complete "The Tavern"
  
  • Failure
    
  • Huge Success
    
  • Defeat the King of Dust
    
  • "Attack the Captain!
  
  
• Complete "Pirate Map"
  
• Complete "Mysterious Parchment"
  
  • Requires 150! Gold
  
  
• Complete "Caustic Geysers"
  
  • Requires you to wear gloves
  
  
• Complete "Pilgrimage"
  
  • Requires 50! Food
  
  
• Complete "High Priestess"
  
  • Requires you to have 4 blessings upon you
  
  
• Complete "Petward the Monk"
  
  • Get a Failure (2/4), while you have at least 111 Health

If you've unlocked the equipment, refer to this guide for further tips:
https://steamproxy.net/sharedfiles/filedetails/?id=1500523524

Well Travelled
Unlock every encounter card.

--- w/ Apprentice?: Yes, unlockable

Well Equipped
Unlock every equipment card.

--- w/ Apprentice?: Yes, unlockable

This one will take quite some time. Just complete encounters until all of them are unlocked.
Make sure, that the token symbol on the bottom of each encounter card is gone, in order to confirm, that you got the rewards from that encounter.

It's important to mention, that, while you do NOT need the class-bound encounters from the DLC, you DO need the all the encounter cards tied to the Apprentice and the Warlord!

Graduation
Complete all Apprentice encounters.

• Encounter 1-3: complete the given tutorials (unfailable)

Lord of War
Complete all Warlord encounters.

• Encounter 1: __auto-completed
  
• Encounter 1.5 - "Warning Signs": Survive the encounter
  
  
• Encounter 2: You need to have the "Disciple's Ring" equipped.
  In order to unlock the ring, you need to:
  
  • Defeat the Queen of Skulls
    
  • Clear the "Dark Ritual" encounter
    
  • Clear the "The Lich" encounter
  
  
• Encounter 2.5 - "Captain's Woes"
  
  • Choose "Yes, help him get his crew back"
    
  • Defeat a Lich + X of Skulls
• Encounter 2.6 - "The Curse of Davey Jones" - Win a game of chance, with a 2/4 chance
  
  
• Encounter 3: Skeleton King set equipped.
  
  • Requires "Skeleton King Sword", "Skeleton King Shield" and "Skeleton King Helm"
    
  • You unlock all 3 equipment cards by defeating the King of Skulls
    
  • (This will also unlock you the "King of the Undead" Achievement)

For encounter 3:
ONLY put the 3 skeleton items into your equipment deck and fill everything else with rings & artifacts. And make sure to use the following encounters:

• Twisted Canyon
  
• Mister Lionel
  
• Trading Post
  
• Holy Quest

Dungeon Conqueror
Defeat the Dealer as the Warlord.


Well, defeat the Final Boss, using the Warlord...
Good luck!


Deep Delver
Reach level 30 in Endless Mode.

--- w/ Apprentice?: Yes, unlockable

Self-explanatory. Do this after you've beaten all regular bosses.
Put everything you've learned to use.
Good luck.

------------------------------------------------------------------------------------------------------



The following achievements will all follow the quest-lines above.

Vault Raider
Complete the Goblin King's Halls IV encounter

--- w/ Apprentice?: Yes, unlockable

The "Goblin King's Halls" quest-line includes:

• Goblin King's Halls I
  
  • "Ask him to elaborate." -> "Accept the task."
  
  
• The Maiden
  
  • "Request a lock of hair from the elf maiden."
  
  
• Goblin King's Halls II
  
  • Go into the maze as often as needed to satisfy Lionel.
  
  
• Goblin King's Halls III
  
  • Find the treasure in the maze and leave it alive.
  
  
• Goblin King's Halls IV
  
  • Find the treasure in the maze and leave it alive.

Great Hunter
Defeat the White Minotaur

--- w/ Apprentice?: Yes, unlockable

The "White Minotaur" quest-line includes:

• The Song of the White Minotaur
  
• Hunting the Huntsman
  
• The Mug and Barrel
  
• Tracks in Town
  
• The Labyrinth
  
  • This one will also unlock you the "Release the Minotaur!" achievement
• The White Minotaur
  
  • This one will unlock you the "Great Hunter" achievement

World Saviour
Turn back the invasion from the Underworld.

--- w/ Apprentice?: Yes, unlockable

The "Underworld" quest-line includes:

• Indecent Arrival
  
  • "Follow." -> "Interrupt."
  
  
• Alicia in Underworld
  
  • You need to have an artifact equipped!
    
  • "Explain your interest [...]"
    
  • Pay 3 Gold - as often as needed to get the "Huge Success" afterwards, with a chance of 1/4
    
  • Give her the artifact.
  
  
• Greenborough Forest
  
  • You need a weapon with MORE than 25 damage,
    
  • and 3 rings in your inventory.
  
  
• Descent into the Underworld
  
  • This encounter can be revisited. Do so, as often as needed to unlock the Achievement

The Elder Lizard
Trade with the Elder Lizard.

--- w/ Apprentice?: Yes, unlockable

Kraken Master
Defeat the Kraken.

--- w/ Apprentice?: Yes, unlockable

One with the Kraken
Equip the Kraken Sword and Mask at once.

--- w/ Apprentice?: No, LOCKED

Now, this quest-line is a little bit more complicated:

• The Land Locked Lubber I
  
  • __auto-completed
• Smugglers Wharf
  
  • Get the info. Easiest way is to pay 30 gold, then another 20.
• The Land Locked Lubber II
  
  • Choose any of the pay options
• Meet the Highbinder
  
  • This will unlock 2 separated branches to follow:

• First, follow the quest-line above until you've completed "Meet the Highbinder".
  
• The Land Locked Lubber III
  
  • __auto-completed
• The Kraken Cult
  
  • Get a Success, with a chance of 3/4
    
  • Choose to get closer, but Fail! with a chance of 3/4.
    
  • Choose to aid the Lizardman.
• Trial by Combat
  
  • Get a 30-hit combo. Just spam shield-bash (stun) against one of the lizard.
    
  • Even though this will only unlock the encounter at which you were supposed to trade, this will actually unlock you the The Elder Lizard achievement!

• First, follow the quest-line above until you've completed "Meet the Highbinder".
  
• The Tavern Attack
  
  • Defeat a King of Dust and Queen of Dust, simultaniously
    
  • Defeat the Jack of Dust and the 3 Mages
• The Land Locked Lubber IV
  
  • __auto-completed
• Sea Journey
  
  • Get all of the required successes
• The Kraken Unleashed
  
  • Defeat the Kraken
    
  • This will unlock you the Kraken Master achievement.
    
    
  • You'll immediately receive the Kraken Mask.
    
  • But you'll only receive the token for the Kraken Sword.
    
  • --> This means, you'll have to do the Kraken encounter again, with the Kraken Sword as a part of your deck...
    
  • Make sure NOT to play the Apprentice for the One with the Kraken achievement.

For all of these achievements, you need to play the class given in the description of the respective achievement.


Elite Training
Complete all Soldier's Training encounters.

• Encounter 1: land a 15 hit combo
  
• Encounter 2: land a 20 hit combo
  
• Encounter 3: land a 30 hit combo

Master of the Shadows
Complete all Shadow Agent encounters.

• Encounter 1: __auto-completed
  
• Encounter 2: You need to have the "Guild Master's Ring" equipped.
  
  In order to unlock the ring, you need to:
  
  • Defeat the Jack of Skulls
    
  • Clear the "Crucible" encounter
    
  • Clear the "Noble Trader" encounter, by selling him a weapon, shield or armor obtained during the session
    
  • Clear the "Lovers" encounter, by helping them (even for a price)
    
  • Clear the "Angry Guild Master" encounter, by successfully stealing from him
  
  
• Encounter 3: __auto-completed
  
• Encounter 4: Win 3 games of chance, with a 2/4 chance each
  
• Encounter 5: __auto-completed
  
• Encounter 6: Win 1 game of chance, with a 2/4 chance
  
• Encounter 7: Win 2 games of chance, with a 2/4 chance each.
  -> Go for the river route!
  
• Encounter 8: __auto-completed

The Wanderer
Complete all Nomad encounters.


For all 3 encounters, choose: South, East, East, South, South (thanks to the HoF Wiki)

• Encounter 1: choose the right path (above)
  
• Encounter 2: choose the right path (above)
  
• Encounter 3: choose the right path (above), and defeat the King of Dust

The Lion Prince
Complete all Curse of the Lion Prince encounters.

• Encounter 1: You need >120 max health
  
• Encounter 2: You need >120 max health, as well as >80 current health
  
• Encounter 3: You need >120 max health, as well as >80 current health and have the starting curse removed

Explorer
Complete all Explorer's Gift encounters.

• Encounter 1: You need to pay 40 Gold
  
• Encounter 2: You need to make enough progress. Choose:
  
  • Sail around the storm
    
  • Ignore them.
    
  • Offer them 25 gold. (Discuss the island with your crew, if you don't have the gold)
• Encounter 3: Defeat the Jack of Scales.
  -> Before you can even start this encounter, you need to have beaten the Jack of Scales 'campaign'

Merchant's Saviour
Complete all Merchant Guard encounters.

• Encounter 1: Choose "Question the merchant more" and get the "Success", with a 1/4 chance
  
• Encounter 2: Choose "Ask him about his gang" and get the "Huge Success", with a 1/4 chance
  
• Encounter 3: Defeat the King of Plague

Never Enough
Complete all Hoarder's Desire encounters.

• Encounter 1-3: Give the goblin all of your equipment. You need to have at least 1 item equipped, which you aquired during the session.

Holy Champion
Complete all Monk encounters.

• Encounter 1: __auto-completed
  
• Encounter 2: Defeat the Jack of Skulls
  
• Encounter 3:
  
  • Before you can even start this encounter, you need to have beaten the Queen of Skulls 'campaign'
    
  • Get a "Failure" with a chance of 3/4
    
  • Followed by the "Huge Success" with a chance of 1/4
    
  • Defeat the Queen of Skulls
• Encounter 4:
  
  • Get the "Huge Success" with a chance of 1/4.
    
  • Fight and defeat a Jack of Skulls, a Queen of Skulls and a King of Skulls simultaniously

Hunger Satiated
Complete all Iron Hunger encounters.

• Encounter 1: __auto-completed
  
  
• Encounter 2: Give the Alchemist 25 Iron Ore
  
• Encounter 3: __auto-completed
  
  
• Encounter 4: Give the Alchemist 50 Iron Ore
  
• Encounter 5: __auto-completed
  
  
• Encounter 6: Give the Alchemist 100 Iron Ore
  
• Encounter 7: __auto-completed

For advices on how to get the Iron Ore efficiently, check the next chapter:

Metal Mogul
Possess 300 or more Ore.


Okay, so - I started by reading the following guide. It was really helpful, so please leave a like there:
https://steamproxy.net/sharedfiles/filedetails/?id=899191148
I modified the strategy described in the guide above and used the following decks:

Equipment (IO = Iron Ore)


Encounter - play all of them regularly; the way which awarded you their tokens:


With these cards selected, start the Queen of Skulls campaign.
Yes. We will NOT play Endless Mode.
The Queen of Skulls campaign comes with the Merchant Guild blessing "curse", which reduces buying prices considerably. Together with the Guild Ring, the prices in the shop are just 1 gold higher than the Iron Ore you get from smelting.
And while the Endless Mode keeps on throwing deadly/useless encounters and worthless equipment at you, every single card in Queen of Skulls is useful.


Now, while playing the 5 floors of Queen of Skulls, you need to:

1. Aquire the Guild Ring
   
   • Starting item
     
   • The Lovers - help, but only for a price
     
   • or just some dumb luck with equipment gain cards
   
   
2. Remove the "Haunted" curse.
   This can be done in 2 ways:
   
   • "Soul Gem" encounter - has a 1/2 chance of removing "Haunted"
     -> Though if it removes "Merchant Guild", you can forfeit immediately...
     
     
   • "Ghost of the Sea" encounter - has a ~1/8 chance of removing ALL curses.
     -> IF you go for the ghost, the shops on the current floor will keep their reduced prices, but all shops on further floors won't. Only use this, if you already have enough gold.
   
   
3. Accumulate ~300 gold. Combined with the Iron Ore you already got from equipment gain cards, that should be enough. Just revisit the shop on the last floor over and over, and keep buying all available items, until this achievement pops up.

Here's the deal:
I've tried this several times. I always Alt+F4'ed the game, whenever I got a failure on an encounter. This way, I've always accumulated enough gold (- way more than that, actually). Really the only problem here is to get rid of the "Haunted" curse.
Alt+F4 only works, if the encounter card hasn't been placed back on the floor, though. So you can't manipulate the Soul Gem...
You're welcome to play this regularly, but you might need several more tries that way.

Good luck!

That's it. Good Luck obtaining all the achievements!

And thanks to Brachragon for his massive overhaul of the guide!