Seasonal SLS Bridge 1.4.2

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.

Community & support

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

https://discord.gg/kN3cqHqWYA

What's new in 1.4.2

Version 1.4.2 is a small compatibility update adding explicit support for StarLevelSystem 1.18.0.0.

No seasonal logic, probabilities, titles, ecological behavior or visual selection rules have changed in this release. The custom visual pack from 1.4.1 remains unchanged and continues to include finished textures for the Troll, Greydwarf family and Skeletons.

Visual System

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

Current artwork status: fully finished public custom textures are currently included for the Troll, the Greydwarf family and Skeletons.
The broader visual framework and creature catalog are already prepared for additional families, which will continue to be added gradually.

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 screenshots below remain the current public showcase. Version 1.4.1 also includes completed custom textures for the Greydwarf family and Skeletons.

Fire — Sumarbarn

SoulEater

Poison — Várbarn

Elemental Chaos

Lightning — Haustbarn

Frost — Vetrbarn

Configuration

Configuration file:

BepInEx/config/TheLionCid.SeasonalSLSBridge.cfg

Main settings:

Setting	Default	Description
SeasonalRollChance	100	Percentage chance for a spawned creature to receive a seasonal modifier.
DelaySeconds	0.75	Delay before the seasonal modifier is applied after spawning.
IncludeTamed	false	Whether tamed creatures can receive seasonal modifiers.
LogAppliedModifiers	true	Logs successful seasonal applications.
EnsureSeasonalModifier	true	Fills empty valid rolls with the seasonal Minor fallback.
Visuals.Enabled	true	Enables or disables the local visual system.
Visuals.TextureFilter	Point	Texture filtering mode. Point preserves vanilla pixel detail; Bilinear/Trilinear can be used for HD packs.

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
• 1.17.0.0
• 1.18.0.0

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

The community Discord is linked near the top of this README. 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.