When you've completed this guide, you'll know:

• Where to look when you want to create, edit or move skills
  
• What the columns mean when viewed in Pack File Manager (hereafter referred to as PFM)
  
• A method to efficiently edit or add to achieve the desired change
  
• Pitfalls to avoid (Basic Tribal Knowledge)

• Pack File Manager available from https://sourceforge.net/projects/packfilemanager/
  
• A Text Editor (Preferably one that has Find&Replace, I recommend Notepad++)

When looking at the tables for the first time, it's easy to get overwhelmed with huge names, vague descriptions of fields, and the massive numbers of entries. To make this easier to understand, I'm going to compare the image of a character's skill tree in game to the table entries for it.


Here's the entries for Ungrim in PFM (under character_skill_nodes_tables), and how the skills are arranged in-game to show the effects of indent and tier. Note that in PFM, Ungrim's fighting skills are in indent 1, but look like they're in indent 2. This is because there's nothing in indent 2 and 3, so the game intelligently centered it.

Treat Indent as Row, and Tier as column. In this way, you can treat it like a spreadsheet. Just like a spreadsheet, you have empty indents and rows, which character_skill_nodes_tables fills out based on the indent and tier provided. The game will ignore empty tiers and skills assigned to be hidden (unchecked in the PFM pic) and snap everything to the left side of the skills screen, whether it looks pretty or not. Tier number goes up from left to right. Indent goes up from top to bottom.

What about the arrow from the left skill to a box containing four more skills? That's handled by character_skill_node_links_tables, image below.
Child key is the Container unlocked by points in the Parent key Container(s). The column labeled Unknown7 is the type of requirement. I use the term Container because these don't point to the real skill (that's defined by character_skill_nodes_tables) but to the container (the column labeled key in character_skill_nodes_tables, which MUST BE UNIQUE AND USED ONLY ONCE IN CHARACTER_SKILL_NODES_TABLES) (caps for emphasis).

The first four rows have the same Parent Container, wh_main_skill_node_dwf_ungrim_battle_01, with Child containers 02, 03, 04, and 05 of the same name. They all say REQUIRED in Unknown7. The first row says that 01 (which contains Full Plate Armor) is required for 02 (contains Resolute) to be available. The second row says that 01 is required for 03 (contains Hard to Hit) to be available, and so on. In this way, you can't take these four skills unless you have a point in Full Plate Armor.

Onto the second four rows. These have the same Child Container (06 (contains Foe-Seeker)), with different Parent Containers, namely 02, 03, 04, and 05. They all say SUBSET_REQUIRED in Unknown7. What this is saying is that for 06 to be available, a specific number of skill points between those four containers (Resolute, Hard to Hit, Scarred Veteran and Ancestral Grudge) must be invested. How many is actually stated back in character_skill_nodes_tables. If you look at battle_06 in the first PFM image, there's a column with 4. This is the number of points required to satisfy the subset requirement.

The next four rows and final row follow the same progression. 06 unlocks 07, 08, 09, and 10, and four points between these four unlocks 11.

That by itself is enough background to create a basic skill mod. There's more to it if you want to edit or create spells/skills of your own, but for giving a lord or hero the skills you want, these two files are all you need to look at (with one exception I'll go into later).

Here I'm going to do a step by step of how you can go about creating one of the mods I've done, "Vampire Lords Dual Magic Affinity" We'll be copying entries from and to PFM and a text editor. The text editor is for doing some find and replace work to make this much faster and much less painful.
*Note that this is using Notepad++. Depending on your editor it may not carry everything over, and if it does not then you'll need to deal with the columns individually.

• Open the file menu, go to My Mods, and select New.
  
• Name your mod
  
• A window will open, in your TW:Warhammer data directory, select data.pack.
  
• Scroll down the list of tables, open character_skill_node_links_tables, double click data_core, open character_skill_nodes_tables, and double click data_core there too. Then hit ok. The two tables will be placed in your new mod.pack.
  
• Right click on data_core for both tables click rename and rename it to something that is not data_core. This way you won't break your game by forcing the original data_core not to load. We will be deleting a lot of entries in our new mod.
  
• Scroll down the right window until you start seeing vmp_mannfred in character_skill_node_set_key. Find the ones labeled magic_death in character_skill_key.
  
• Copy these entries (click on the space left of 2062, shift click the space left of 2069, then hit control+C). Paste these entries into your text editor (Control+V)
  
• Do a replace operation with your text editor (Control+H on Notepad++). You must create new containers for your vampire lord to use. You can only assign a container to one character. For example, replace mannfred with lord. This will replace mannfred in both the key and character_skill_node_set_key columns.
  
• Copy everything from your text editor.
  
• Go back to PFM, control+a and delete all of the entries in character_skill_node_set_key. You should now only see a single line with a *.
  
• Click to the left of that star, and paste. There should now be only the table from the text editor with your edited values.
  
• Save and exit PFM, then load it back up. This gets around an issue with PFM where it doesn't want to update the db files and it won't recognize your new keys.
  
• Now go to character_skill_node_links_table. Scroll down and find mannfred again. Copy the rows dealing with magic2.
  
• Paste this to an empty file in your text editor.
  
• Do a replace operation again. Replace mannfred with lord. Copy your changed table.
  
• Go back to PFM, empty out the contents of character_skill_node_links_table.
  
• Click to the left of the star in the single line remaining, and paste.
  
• Save your changes.
  
• Install and test. Your Vampire Lords should now have Death Magic in addition to Vampire Magic.

With this, there was no need to change indent or tier, or to mess around with the flow of the links table. If you're adding to other characters, however, you need to make sure you don't accidentally overwrite their skills with yours. If you want to create a node that doesn't exist in game, you'll need to set it up using what you learned from the previous section.

This section exists to inform others of issues I ran into while making hero skill changes.

• You have to create new keys in character_skill_nodes_tables. You cannot simply clone the entries and change the node_set_key to who you want to get it. If you do this, what will happen is that whoever you took the skills from will lose access to those skills.
  
• Raise Dead has an additional requirement for non-Vampire Counts races. If you want to give this spell to someone not of the Vampire Count race, you must include culture_to_battle_animations_tables_tables, and add:
  hu1_skeleton_sword_and_shield
  hu1_vampire_zombie_sword
  hu1_vampire_zombie_sword_draught (not sure if this is required but doesn't hurt)
  to the race of your choice (for example, wh_main_grn_greenskins to give the animation for them to the greenskins). You will know you haven't done this when you cast the spell with lord or hero in game and you summon reference poses that skate around (which honestly would freak me out IRL more than zombies to see, but anyway...)
  
• Magic is set up so that characters get their first spell for free. This is due to the existence of an invisible dummy skill that enables the spell. If you do not wish characters to get their first spell for free, you must include character_skill_level_to_effects_junction_tables, clone the enable_x (x being the spell) key connected to the dummy skill key, and rename the cloned dummy to the first level of the spell. Then you can go to character_skill_nodes_tables and delete the dummy skill. If you just delete the dummy skill, your lords/heros will not be able to cast the first spell.