What does the full castle upgrade tree look like?

Question

I hate spending money blindly on castle upgrades just to find out what it unlocks, because it's just a waste of money when what I unlock isn't something I want buy. Plus there are times where I'd like to unlock specific upgrades (like the class upgrades) and knowing the shortest path to unlock it would be very useful.

To this end I'd like a list of the castle upgrades and the skills required to unlock each upgrade. An answer making use of an image similiar to this XCOM research tree would be ideal.

Answer 1

Okay, I've made you a flowchart of what upgrades unlock what. It takes only 1 point in an upgrade to unlock the next ones. If there are any upgrades which have multiple requiements, this may be off. You may have to open the image to see it easily.

Answer 2

I realize this doesn't show which are prerequisite for each other like you wanted, but it does at least show what's available and where. Just unlock stuff in the direction of what you want. I can't nail down exact prerequisites without a new playthrough.

1. Death Defy - Give you a small chance to defy death and come back to life with a few hp when you die.
2. Upgrade Lich - Turns Lich into Lich King. Lets you convert some max HP into max MP.
3. Unlock Lich - They increase max hp by 4 (up to a certain cap) when they kill an enemy.
4. Upgrade Shinobi - Turns Shinobi into Hokage. Gives you the Flash ability, which is like a really short range teleport which doesn't go through walls.
5. Haggle - Charon lets you keep some of your money when you enter the dungeon.
6. Unlock Shinobi - A high damage class.
7. Crit Chance Up - Improves % chance to crit.
8. Upgrade Barbarian - Turns Barbarian into Barbarian King. Gives him a shout ability that damages objects and enemies slightly, and pushes them back.
9. Architect - He'll appear outside the dungeon, and will lock the dungeon down to its previous version for you, but you'll make less gold (70%) as a result.
10. Attack Up - Raises your strength.
11. Crit Damage Up - Raises % damage bonus on crit.
12. Down Strike Up - Raises damage of the downward thrust attack.
13. Armor Up - Raises your armor score.
14. Equip Up - Raises your encumbrance so that you can equip heavier items.
15. Upgrade Knights - Turns Knight into the Paladin. They have a special ability where they can raise their shield to block attacks. Blocked attacks drain MP.
16. Health Up - Raises your hit point total.
17. Smithy - Blacksmith appears outside the dungeon and lets you buy items from blueprints or change your equipped gear.
18. Mana Up - Raises your max mana.
19. Beastiality - Unlocks the half dragon class.
20. Invuln Time Up - Increases the amount of time you are invulnerable after taking damage.
21. Upgrade Spell Thief - Turns the Spellthief into a Spellsword. Gives them an ability to cast a larger version of the spell for twice the mana cost.
22. Unlock Spell Thief - Unlocks the Spell Thief class, which gets mana upon killing enemies.
23. Mana Cost Down - Lowers the mana cost of spells.
24. Potion Up - Increases the effectiveness of food and potions.
25. Upgrade Knave - Turns the Knave into an Assassin. They have a stealth ability that makes them invisible but eats mana quickly.
26. Upgrade Mage - Turns the Mage into an Archmage. Instead of just one spell, they get 3 and swap between them with their skill button.
27. Enchantress - Lets you visit the Enchantress outside the dungeon, from whom you can buy and equip runes that you find in the dungeon.
28. Magic Damage Up - Increases the damage of magic attacks.
29. Randomize Children - if you don't like your three character choices for a generation, you can randomly reroll the three of them (once per generation).
30. Unlock Miner - The miner class has low stats but has increased gold gain (I think 30%).
31. Gold Gain Up - Increases the amount of gold that all characters receive by 10% per skill level.
32. Upgrade Miner - Turns the Miner into a Spelunker, who gets a fancy mining hat.

Answer 3

Maybe some pictures might help? SPOILERS FOR ANY THAT LOOK!