Skill nodes and perks

A mod adds skill tree nodes, each copying a vanilla node’s effect and icons at a place of its own, linked from vanilla or mod nodes, and perks copied from vanilla perks with texts of their own.

A node of the mod’s own

load.skill_nodes() lists the game’s nodes: each one’s id, kind (Root, Attribute, ActiveSkill or PassiveSkill) and place. On server 399 the tree has 243 nodes, 12 of them roots.

load.add_skill_node(NewSkillNode) adds a copy of the vanilla node like:

Field	What it sets
id	the node’s content id
like	the vanilla node whose effect and icons it copies
x, y	where the tree screen draws it
links_from	the nodes it is unlocked from, vanilla or a mod’s
name, description	its texts’ tags
cost	the skill points it costs; nil keeps the vanilla node’s
max_level	0 for a copy of a node with levels; nil keeps the vanilla node’s
kind	what it is; nil keeps the vanilla node’s

A player unlocks it with skill points as the game’s own nodes. The tree screen draws it from the data on the client, so a mod that adds one runs on both sides.

use enshwick::content::id;
use enshwick::content::skills::NewSkillNode;
use enshwick::typed::SkillNodeType;

fn init(load: &mut enshwick::Load<'_>) -> Result<(), enshwick::Off> {
    let tree = load.skill_nodes()?;
    let root = tree.iter().find(|node| node.kind == SkillNodeType::Root);
    let stamina = tree.iter().find(|node| node.kind == SkillNodeType::Attribute);
    if let (Some(root), Some(stamina)) = (root, stamina) {
        load.add_skill_node(NewSkillNode {
            links_from: vec![root.id],
            cost: Some(1),
            ..NewSkillNode::new(id!("endurance"), stamina.id, root.x + 120.0, root.y, id!("endurance.name").guid(), id!("endurance.text").guid())
        })?;
    }
    Ok(())
}

How many nodes fit

A player’s save keeps a fixed count of unlocked nodes: 256 on server 399, as the running server’s reflection reports. The game’s tree takes 243 of them, so 13 nodes fit for every mod together, in load order. A node beyond the room returns Err(Off) when the game’s own tree is full already; past other mods’ nodes, the loader leaves it out when the game first reads the tree. On a server copy of server 399, the 14th node of a mod was left out this way.

Each node shows as the mod’s feature skill node <id> in the status summary and on the Mods screen, with the reason when it is refused or left out.

A node closer to another than half the vanilla tree’s smallest gap between two nodes returns Err(Off): on server 399 that gap is about 103, so a node keeps about 51 away from every other, mods’ nodes included. A place that is not a finite number, a node linked twice from one node, and a node with levels also return Err(Off). The game keeps a node’s levels in a slot of its own (levelIndex), which a copy would share with its vanilla node, so a copy of a node with levels sets max_level to 0.

A perk of the mod’s own

load.add_perk(NewPerk) copies the vanilla perk like under the mod’s id, with its own name and description, and lists it beside the game’s perks.

These calls need the typed feature.

From Luau

The same calls are enshwick.content.skill_nodes(), enshwick.content.add_skill_node{...} and enshwick.content.add_perk{...}, at the top level of main.luau.

local nodes = enshwick.content.skill_nodes()
local root, stamina = nodes[1], nodes[2]
enshwick.content.add_skill_node({
    id = "you.skills:endurance",
    like = stamina.id,
    x = root.x + 120,
    y = root.y,
    links_from = { root.id },
    name = enshwick.content.guid("you.skills:endurance.name"),
    description = enshwick.content.guid("you.skills:endurance.text"),
    cost = 1,
})