Stardew Valley NPC Guide 0.06

So, you're interested in adding new characters to Stardew Valley, and want to do so using xnb files?
This is a simple option that should allow you to add relatively feature-complete NPCS into the game itself, so let's get to it.

First, if you do not know how to extract and repack xnb files, please consult this tutorial by cantordsdust!
http://imgur.com/gallery/WCfeO/

Ready?
In full, you'll need to alter the following files and repack them:

-Data/animationDescriptions, for if your spritesheet has custom animations. This can be anything from calling a sprite 'sitting' or 'drinking' to a surprised jump in the air.
-Data/EngagementDialogue, for if your NPC is marriageable using the in-game marriage system.
-Data/Locations, if you're planning to use a custom location. New maps will also have to be edited if you're planning to create a custom location, in which case you'll also need to know how to edit .tbin files and the associated spritesheets.
-Data/mail, if you want your NPC to mail the player.
-Data/NPCDispositions: *THIS ONE IS IMPORTANT! Indepth look blocked off with asterisks.
***

First, let's take a look at a feature-complete NPC:

Robin: "adult/neutral/outgoing/positive/female/not-datable/Demetrius/Town/fall 21/Demetrius 'husband' Maru 'daughter' Sebastian 'son'/ScienceHouse 21 4" #!String

Adult defines the NPC as an adult; not sure what that does, suspect it's a dialogue call. Other values are teen and child.

Neutral defines the courtesy of the NPC. Other values are rude and polite.

Outgoing is how likely the NPC is to interact when someone enters into their line of sight. Other values are shy and neutral.

Positive is the likelyhood for the NPC to emote receptively or depressively. Other values are negative or neutral.

Female defines a female character; other values are male or undefined.

Datable is whether the NPC is datable in-game, using the in-game engine. Other values are not-datable.

Demetrius's place marks the in-game spouse or partner of a character. Interestingly, even though many of the defines here are seemingly unimportant, certain characters are paired off within.

Town is where the NPC originates from. Other values are Desert and Other. I suspect Other is vital for loading NPCs from the 'Temp' location, but don't quote me on this.

fall 21 is Robin's birthday; any in-game date will work, but I imagine conflicts occur for multiple NPC's sharing a birth date.
The section defining husband, daughter, and son hallmarks in-game relations. This can be called so that Robin will say 'if you want to impress my husband, bring him a strawberry!' instead of 'if you want to impress Demetrius, bring him a strawberry!'
You can also keep the section blank.

ScienceHouse 21 4 is the location and tiles where NPC's 'live'. Again, you're familiar with this, but it's important to understand.

Here's Thelma:

Thelma: "adult/polite/shy/negative/female/datable/null/Other/spring 13//Tent 1 3" #!String
Ignore the fact she's trying to kick Linus out of his place right now. That's just because it's an easily accessable area and I'm lazy.
Let me know if you see any errors I've missed!

***

NPCGiftTastes, which tells an NPC how to react with dialogue and gift information.
The formatting is text/objectID.
Example:
Robin: " This is for me? Wow, I absolutely love it!!/224 426 636/Thanks! This is really nice!/-6 -79 424 709/Um... why?/16 330/What the...? This is terrible!/2/Thank you. This might come in handy.// " #!String

Lovetext, objects, liketest, objects (grouped by pairing in some cases), concernedtext, objects, hatred, object, and neutral (with no objects defined. I suspect this mean if it doesn't fall into the other categories it auto-defines as neutral.)

Finally, you need to edit and re-pack the festivals you want the NPC to appear at, if you plan to have them appear at festivals.

Next!
These files should, I believe, be created and packed originally.
However, the game has of yet refused to acknowledge newly created files, so unless I'm missing a define it may be necessary to repack an NPC *OR* create the NPC as an inspectable object.
All files should share the same name, which should be the name of the NPC; in my case, Thelma.

Characters/Thelma.xnb, which contains Thelma.png and Thelma.yaml; this is a spritesheet.
Here's an example of a 'feature-complete' spritesheet, with several sprites that move in animated sessions as defined by animationDescriptions:
Robin's Spritesheet - http://i.imgur.com/SByYcAT.png
And here's Thelma's - http://i.imgur.com/OnpBz2Y.png
You can put and laugh if you want to, you can leave your friends behind;
Cause I don't dance and if I don't dance nobody's a friend of mine.

Characters/Dialogue/Thelma.xnb, which contains Thelma.yaml.
The dialogue file for dialogue about town; I've only got the introduction text here, but it's not too hard to format; even for someone who only works with python like I do. You can also repack MarriageDialogue for MarriageCandidates, but stick to basics first. Dialogue can be called lots of ways and refer to lots of strings, and is the cornerstone of my attempts to evade the hard limits I'd have to otherwise use an API for.

The numerous sub-season folders are sometimes called in the wrong season; you've probably had Evelyn mention leeks even in the dead of winter. I'm not sure why this is, but if someone figures out why, let CA know. It's unimportant and kind of amusing, but probably not intended.

Portraits/Thelma.xnb, which contains Thelma.png and Thelma.yaml.
Again, for comparison, here's Robin's - http://i.imgur.com/CX7obG8.png
And here's Thelma's - http://i.imgur.com/rpJXvYp.png

Characters/Schedules/Thelma.xnb, which contains Thelma.yaml. This is IMPORTANT as it dictates where your NPC is going to move around.

I suspect this is what's causing Thelma to not show up anywhere, if I haven't accidentally submerged her in the void beyond the tent.
The format is time, in military hours, location, and tile. You can also include dialogue - amongst other things.

Yet again: Robin's -

content:  #!Dictionary<String,String>
    rain: "800 ScienceHouse 8 18 2/1700 ScienceHouse 29 9 0/1930 ScienceHouse 16 5 0/2100 ScienceHouse 21 4 1" #!String
    Mon: "800 ScienceHouse 8 18 2/1200 CommunityCenter 9 19 3/1600 ScienceHouse 16 5 0/2100 ScienceHouse 21 4 1" #!String
    Tue: "930 SeedShop 27 18 0/1300 SeedShop 27 22 2 robin_exercise/1600 SeedShop 24 16 0 \"We meet every week to encourage each other to stay healthy.\"/1800 ScienceHouse 16 5 0/2100 ScienceHouse 21 4 1" #!String
    summer_18: "700 ScienceHouse 8 18 2/800 Hospital 12 14 0 \"What's a healthy young person like you doing here?\"/1330 Hospital 4 6 1 \"Nothing bad to report, Doc. I feel as healthy as ever.\"/1600 ScienceHouse 16 5 0/2100 ScienceHouse 21 4 1" #!String
    Fri: "800 ScienceHouse 8 18 2/1600 Saloon 22 22 1/1920 Saloon 23 22 1 robin_dance/2100 ScienceHouse 21 4 1" #!String
    spring: "800 ScienceHouse 8 18 2/1700 Mountain 29 36 2/1930 ScienceHouse 16 5 0/2100 ScienceHouse 21 4 1" #!String

And Thelma's, obviously just here so that I can try to get her in-game.

content:  #!Dictionary<String,String>
    spring: "Tent 1 3 1/1500 Saloon 10 18 1/2300 Tent 1 3 1" #!String
    summer: "Tent 1 3 1/1500 Saloon 10 18 1/2300 Tent 1 3 1" #!String
    winter: "Tent 1 3 1/1500 Saloon 10 18 1/2300 Tent 1 3 1" #!String
    fall: "Tent 1 3 1/1500 Saloon 10 18 1/2300 Tent 1 3 1" #!String

If you've got more information or ideas, feel free to contribute them and I hope this helps you in your own work adding more interesting NPC's to Stardew Valley!