Seasonal SLS Bridge 1.4.0

Seasonal SLS Bridge connects Seasonality with StarLevelSystem to give Valheim's creatures seasonal combat traits and optional visual variants.

The goal is simple: make the world feel more alive and less predictable without changing StarLevelSystem itself, replacing its modifier names, or taking control away from Seasonality.

What's new in 1.4.0

Version 1.4.0 introduces the first public release of the new visual system.

Creatures can now receive local visual variants that match some of their StarLevelSystem modifiers while keeping the existing seasonal and ecological behavior of the bridge.

Highlights:

• Optional local creature visuals linked to seasonal and StarLevelSystem modifiers.
• The visual framework/catalog is prepared for 23 creature families / 38 prefabs.
• The system supports seasonal visual combinations such as FireNova, PoisonNova and winter Big.
• Generic SoulEater and Brutal visuals that can work in any season.
• Elemental modifiers assigned directly by StarLevelSystem can also use their matching artwork even when no birth season was recorded.
• Deterministic visual priority so overlapping modifiers do not fight for the same creature.
• Support for body textures, eye textures, emission masks and HDR material colors.
• Point filtering by default to preserve Valheim's pixel detail, with Bilinear and Trilinear options for personal HD texture packs.
• Added explicit support for StarLevelSystem 1.16.0, while keeping support for 1.14.0 and 1.15.0.
• Existing seasonal probabilities, titles, ecology, authority rules and persistence remain unchanged.

The visual system is cosmetic. It does not change creature stats, modifier rolls, spawn rates, loot or network gameplay state.

Visual System

The visual system is designed to complement Seasonality instead of replacing it.

Current artwork status: for now, the only fully finished custom creature textures included are for the Troll.
The broader visual framework and creature catalog are already prepared for additional families, but their custom artwork is still a work in progress.

When a supported creature has a matching modifier, Seasonal SLS Bridge can apply a local visual variant for that creature.

Examples include:

• Frost — winter / cold appearance
• Fire — heated or volcanic appearance
• FireNova — more unstable fire appearance
• Poison — toxic / overgrown appearance
• PoisonNova — unstable toxic appearance
• Lightning — storm-charged appearance
• ElementalChaos — unstable arcane appearance
• Big — winter heavy / imposing appearance where supported
• SoulEater — dark generic appearance
• Brutal — aggressive generic appearance

Unedited or unsupported properties are left alone so Seasonality can continue handling its normal seasonal visuals.

Visual priority

If a creature qualifies for more than one supported visual, the bridge uses a fixed priority:

1. Elemental modifiers, with seasonal primary elements taking priority
2. SoulEater
3. Brutal
4. Big

This keeps the result predictable and avoids multiple systems trying to overwrite the same material.

Elemental visual fallback

Elemental modifiers applied directly by StarLevelSystem can still use the matching visual even if the creature has no recorded birth season.

For visual selection only:

• Frost falls back to winter
• Fire, Lightning and FireNova fall back to summer
• Poison, ElementalChaos and PoisonNova fall back to spring

This fallback is visual only. It does not write a birth season, change titles, reroll modifiers or alter gameplay state.

Features

Every eligible new creature stores its birth season.

Season, birth biome and natural affinity determine the seasonal modifier profile.

With the default 100% gate and EnsureSeasonalModifier enabled, an otherwise empty valid roll can use a Minor seasonal fallback:

• Winter: Big
• Spring: Fast
• Summer: ResistFire
• Autumn: Alert

StarLevelSystem must still accept the selected modifier.

Winter — Vetrbarn

Cold-oriented traits are favored:

• Frost
• ResistFrost
• Big
• StaminaDrain
• ResistPierce
• ResistSlash
• ResistBlunt
• EitrDrain

Spring — Várbarn

Spring favors poison, adaptation and unusual mutations:

• Poison
• ElementalChaos
• PoisonNova
• ResistPoison
• Fast
• Evolving
• Splitter

Summer — Sumarbarn

Summer favors heat and aggressive elemental effects:

• Fire
• FireNova
• ResistFire
• Lightning
• Fast
• Brutal
• Big

Autumn — Haustbarn

Autumn favors lightning, poison and spiritual effects:

• Lightning
• Poison
• ElementalChaos
• SoulEater
• ResistSpirit
• Alert
• ResistPoison
• Big

The exact result is weighted, so not every creature receives the same modifier.

Seasonal Creature Names

Eligible new creatures retain their birth-season title independently of the modifier result:

• Esqueleto Vetrbarn
• Greydwarf Várbarn
• Draugr Sumarbarn
• Greydwarf Haustbarn

The bridge does not rewrite StarLevelSystem's modifier names.

The seasonal title is added separately to the creature's hover name.

Screenshots

The Troll is currently the first creature with a complete set of custom visual variants.

Fire — Sumarbarn

SoulEater

Poison — Várbarn

Elemental Chaos

Lightning — Haustbarn

Frost — Vetrbarn

Configuration

Configuration file:

BepInEx/config/TheLionCid.SeasonalSLSBridge.cfg

Main settings:

Existing configuration can be kept when updating. New settings are added automatically.

Custom textures

The visual pack is intentionally lightweight and editable.

Personal PNG edits are preserved by the texture preparation workflow, making it possible to build custom or HD visual packs without changing the gameplay logic of the bridge.

The compact package includes the required texture bases and Preparar-Texturas.ps1 to recreate the editable texture tree.

Requirements

Required dependencies:

• BepInExPack Valheim
• Jötunn
• YamlDotNet
• StarLevelSystem
• Seasonality

Explicitly verified StarLevelSystem versions:

• 1.14.0.0
• 1.15.0.0
• 1.16.0.0

Other versions are not automatically assumed to be compatible.

Installation

Thunderstore

Install Seasonal SLS Bridge and its dependencies through your mod manager.

For the best multiplayer experience, use the same mod version and visual files on the server and clients.

Manual installation

1. Install the required dependencies.
2. Place SeasonalSLSBridge.dll in:

BepInEx/plugins/SeasonalSLSBridge/

1. Place the SeasonalTextures folder alongside the DLL.
2. If using the compact texture package, run Preparar-Texturas.ps1 to generate the editable visual variants.
3. Remove the old experimental TextureTest add-on if it is still installed.
4. Launch Valheim.

Existing creatures are not rerolled when updating.

Only the appropriate server authority applies gameplay changes. Players, bosses, traders and, by default, tamed creatures remain excluded from seasonal modifier application.

Compatibility and design

Seasonal SLS Bridge is intentionally a bridge between existing mods.

It does not:

• modify StarLevelSystem's internal modifier definitions;
• replace StarLevelSystem modifier names;
• edit creature stats directly;
• change spawn rates;
• change loot;
• require manual editing of StarLevelSystem configuration;
• alter Seasonality's season system;
• write network gameplay state just to display a visual variant.

The visual system is local and cosmetic. If a supported texture cannot be loaded, gameplay should continue with the normal creature appearance.

Stability

If the expected StarLevelSystem API cannot be found, the bridge does not attempt unsafe internal modifications.

It reports the compatibility problem and skips modifier application. The creature's stored seasonal identity remains independent from modifier success.

Support, feedback and contributions

For mod questions, bug reports, ideas, texture contributions or general discussion, you can join the community Discord:

https://discord.gg/kN3cqHqWYA

Contributions and feedback are welcome, especially from experienced Valheim/BepInEx modders and texture artists.

AI-assisted development

A significant part of this mod's development, including code generation, debugging, compilation assistance, testing and troubleshooting, was done with the help of AI.

The author, TheLionCid, is not an experienced Valheim mod developer and is publishing this project openly so that more experienced modders can review it, identify problems and help improve it.

Feedback, bug reports and code improvements are welcome.

Permissions

You may adapt or modify this project for your own use, provided that you respect the licenses and credits of this project and its dependencies.

Do not redistribute the work of other authors as your own.

Credits

• TheLionCid — Seasonal SLS Bridge
• MidnightMods — StarLevelSystem
• RustyMods — Seasonality
• ValheimModding — Jötunn and YamlDotNet
• BepInEx / Valheim modding community — modding framework and ecosystem

Disclaimer

This is an independent compatibility bridge. It is not an official component of StarLevelSystem or Seasonality.

Updates to Valheim, StarLevelSystem or Seasonality may require an update to the bridge.