NoArbitraryIncompatibilityFlag

A BepInEx patcher that removes incompatibility restrictions from RtD mods, allowing them to work alongside other popular Valheim mods.

What Does It Do?

This patcher removes [BepInIncompatibility] attributes from RtD mods, enabling you to use them together with mods that were previously blocked. The mods themselves work fine together - this simply removes the restrictions.

Affected RtD Mods:

RtDOcean
RtDVines
RtDMonsters
RtDSouls & RtDSouls_Addon
RtDBiomes
RtDMonstrum
RtDDungeons
RtDFairyTale
RtDGardening
RtDHorrors
RtDItems
RtDMagic

Previously Blocked Mods (Now Compatible):

CookieMilk.MagicalMounts
CookieMilk.MajesticChickens
CookieMilk.BuildPieces
CookieMilk.CarryMeMaster
CookieMilk.DiscordControl
CookieMilk.UltimateServerControl
Therzie.MonstrumDeepNorth
Therzie.WarfareFireAndIce
Therzie.Monstrum
Therzie.Armory
Therzie.Wizardry
Therzie.Warfare
blacks7ar.MagicPlugin
blacks7ar.MagicRevamp
blacks7ar.SeedBed
blacks7ar.OreMines
blacks7ar.BowPlugin
randyknapp.mods.epicloot

Installation

IMPORTANT: This is a PATCHER, not a regular plugin!

Download NoArbitraryIncompatibilityFlag.dll
Place it in BepInEx/patchers/ folder (NOT plugins!)
Launch the game
The patcher will automatically process RtD mods on startup

How It Works

The patcher runs during BepInEx's preloader phase and uses Harmony to patch .NET runtime methods:

Patches PluginInfo.Incompatibilities property getter to return empty array for RtD mods
Patches Dictionary.ContainsKey to hide our GUID when RtD mods check for us
Patches Assembly.GetName() to return a fake name when RtD mods scan loaded assemblies

All modifications are in-memory only and temporary. No files are ever modified on disk.

On launch, you'll see:

✓ Ready to bypass incompatibility checks for RtD mods
✓ Ready to hide from RtD mod detection
✓ Ready to hide assembly name from RtD mod detection
✓ Found RtD mod: RtDOcean
✓ Successfully bypassed incompatibility checks for 1 RtD mod(s)

Technical Details

How RtD Mods Detect This Patcher

RtD mods added three detection checks in their Awake() method:

IL Bytecode Integrity Check: Verifies their "Block" method hasn't been modified

MethodInfo method = typeof(RtDMod).GetMethod("Block", ...);
byte[] ilAsByteArray = method?.GetMethodBody()?.GetILAsByteArray();
if (method == null || ilAsByteArray == null || ilAsByteArray.Length <= 2)
    Fail();

PluginInfo Dictionary Check: Looks for our GUID in BepInEx's plugin registry

if (Chainloader.PluginInfos.ContainsKey("IAmOnTheInternetAndItIsScary.NoArbitraryIncompatibilityFlag"))
    Fail();

Assembly Name Scan: Searches all loaded assemblies for our name

if (AppDomain.CurrentDomain.GetAssemblies().Any(a => a.GetName().Name.Contains("NoArbitraryIncompatibilityFlag")))
    Fail();

How This Patcher Works

The patcher uses Harmony to patch .NET runtime methods at the lowest level:

Incompatibility Bypass: Patch PluginInfo.Incompatibilities getter to return empty array for RtD mods
- Intercepts the property access before RtD mods can read their incompatibility list
- Only affects RtD mods (identified by "Soloredis." GUID prefix)
ContainsKey Stealth: Patch Dictionary<string, PluginInfo>.ContainsKey to return false when RtD mods check for our GUID
- Uses stack trace analysis to identify when the caller is an RtD mod
- Returns false only for our specific GUID and only when called from RtD code
- All other dictionary operations work normally
Assembly Name Hiding: Patch Assembly.GetName() to return fake name when RtD mods scan assemblies
- Returns "HiddenAssembly" instead of "NoArbitraryIncompatibilityFlag" when called from RtD mods
- Uses caching to avoid performance issues from repeated assembly scanning
- Other mods see the real assembly name
IL Check Passes Automatically: We don't modify RtD mod code at all, so their bytecode integrity check passes naturally

FAQ

Q: Is this safe?
A: Yes. The patcher only removes compatibility restrictions. The mods function normally, they just don't block other mods anymore.

Q: Will this break my game?
A: No. If you encounter any issues, they would be unrelated to this patcher. You can always remove the patcher to restore original behavior.

Q: Do I need to reinstall after RtD mod updates?
A: No. The patcher runs on every launch and automatically handles any RtD mod version.

Q: Can I upgrade from an older version of this patcher?
A: Yes. Just replace the old DLL with the new one in the patchers folder.

Q: Will this work with old versions of RtD mods?
A: Yes. The patcher works with all current RtD mod versions.

Q: What if I want to stop using this patcher?
A: Simply remove the DLL from the patchers folder. RtD mods will return to their original behavior.