Forsaken Power Overhaul — Valheim 1.0 Compatibility Port

Original Author: JuneGame
Port Maintainer: momos3939
Original GitHub Repository: JuneGame/Valheim.ForsakenPowerOverhaul
Original Thunderstore Package: JuneGame-ForsakenPowerOverhaul

Important Notice

This is an unofficial, community-maintained compatibility port of JuneGame's original Forsaken Power Overhaul mod, updated for Valheim 1.0 (version 1.0.7+) by momos3939. Full credit for the mod design, original architecture, and gameplay balance belongs to JuneGame. This project is distributed under the original open-source MIT License.

About the Mod

Forsaken Power Overhaul completely rebalances Valheim's guardian powers into a multi-tiered, rewarding progression system. Instead of merely having a situational active ability on a long cooldown, each Forsaken Power provides four distinct components:

• Passive Component: Permanent baseline buffs granted to the player as soon as that boss's trophy is offered at the Sacrificial Stones (e.g. Eikthyr grants permanent stamina).
• Equipped Passive Component: Additional buffs granted while that specific power is equipped (e.g. extra jump height while Eikthyr is equipped).
• Active Component: Potent temporary buffs granted when you activate the power with F.
• Shared Active Component: Secondary buffs granted while any power is active, encouraging synergy and strategic stacking.
• Power Cycling: No need to run back to the Sacrificial Stones to change your equipped power. Press the cycle key (default: G) to rotate through all your currently unlocked powers on the fly.
• World Progression: Access to powers and passive bonuses is tied to your world's boss progression. Hanging trophies at the Sacrificial Stones unlocks them automatically.

What Changed for Valheim 1.0 (v2.2.0)

This port addresses the breaking engine and API changes introduced in Valheim 1.0:

• ZoneSystem Singleton Migration: Replaced all calls to the deprecated ZoneSystem.m_instance field with the new ZoneSystem.instance property getter.
• Ashlands / Fader Support: Integrated Valheim 1.0's Fader guardian power (GP_Ashlands), ensuring passive, equipped, and active powers function across all 7 bosses (Eikthyr, The Elder, Bonemass, Moder, Yagluth, The Queen, and Fader).
• Trinket Slot Integration: Added support for Valheim 1.0's new Trinket equipment slot (m_trinketItem) in equipment movement modifier calculations.
• Adrenaline Mechanic: Updated guardian power activation to support Valheim 1.0's adrenaline boost (AddAdrenaline) upon activation.
• Harmony Overload Disambiguation: Explicitly typed patch target signatures on overloaded Player methods (SetMaxHealth, SetMaxStamina, SetMaxEitr, OnSpawned) to prevent runtime AmbiguousMatchException crashes.
• Equipment Modifiers Return Value Fix: Corrected Harmony postfix return values (ref float __result) for equipment movement and heat resistance modifiers so external systems receive the properly modified values.
• Null Safety Hardening: Added safety checks for ItemStand hover text and ObjectDB status effect icon resolutions to eliminate null reference exceptions during world load.
• Modernized Build Configuration: Rebuilt on .NET Framework 4.8 targeting Jotunn 2.30.0 and BepInEx 5.4.2350 with publicized game assemblies.

Requirements

• Valheim 1.0 (tested on version 1.0.7+)
• BepInExPack Valheim (denikson-BepInExPack_Valheim-5.4.2350 or newer)
• Jotunn, the Valheim Library (ValheimModding-Jotunn-2.30.0 or newer)

Installation

Recommended (Mod Manager):

1. Install via Thunderstore Mod Manager or r2modman with one click.
2. The mod manager will automatically install BepInEx and Jotunn as required dependencies.

Manual Installation:

1. Ensure BepInExPack Valheim and Jotunn are installed.
2. Download the release .zip from Thunderstore.
3. Extract the contents into your Valheim/BepInEx/plugins/ folder (e.g. Valheim/BepInEx/plugins/ForsakenPowerOverhaul/).
4. Launch the game.

Configuration & Presets

• Configuration file: BepInEx/config/JuneGame.Valheim.ForsakenPowerOverhaul.cfg
• The config file is generated on first launch.
• The default preset is Vanilla+. To customize individual stat values, change the Preset setting to Custom.
• Available Presets: Vanilla+, Vanilla, Passive Powers, Custom.
• We strongly recommend using the in-game BepInEx Configuration Manager (F1) for ease of use with the extensive configuration options (over 3,300 lines).

Multiplayer & Server Considerations

• Required on BOTH Client and Server: This mod must be installed on both connected clients and dedicated servers.
• Server-Synced: All stat values, balance settings, and presets are server-synced to ensure fair gameplay across all players.
• Client Settings: The power cycle keybind remains a local client preference.

Verification & Testing

• Static / API Validation: 15 out of 15 Harmony patch targets, game member references, and Jotunn hooks were statically audited and validated against Valheim 1.0 game assemblies using reflection (0 errors, 0 warnings).
• In-Game Runtime Testing: Personally tested and verified by momos3939 in an isolated Valheim 1.0 client test world. Confirmed working: Sacrificial Stone tooltips, boss trophy mounting, passive key unlocking, power cycling (G), power activation (F), compendium UI ($ui_fpo), and equipment modifiers.
• Note: Dedicated server multiplayer testing was not performed directly during development; all verification was completed in single-player test world profiles.

Known Issues / Notes

• Existing Worlds: If installing on an existing world where bosses have already been defeated, visit the Sacrificial Stones once so the mod can scan mounted trophies and award your passive bonuses.
• Mod Compatibility: Incompatible with other mods that alter core Forsaken Power behavior (e.g. Passive Powers or Forsaken Power Plus). Compatible with UI mods like Auga and gameplay overhauls like Epic Loot.

Credits & Attribution

• JuneGame: Original author, designer, and architect of Forsaken Power Overhaul.
  • Discord
  • Ko-Fi
• momos3939: Valheim 1.0 compatibility port maintenance.
• Jotunn & BepInEx Teams: For the essential Valheim modding framework.

License

This project is licensed under the MIT License. See LICENSE.txt for full details.
Original Work Copyright (c) 2025 June
Valheim 1.0 Compatibility Port Modifications Copyright (c) 2026 momos3939