Runic Structures

A Minecraft Forge mod built for the Runecraft modpack that transforms every generated structure into permanently hostile territory. Hostile mobs spawn inside structures around the clock — regardless of light level, time of day, or torches — with randomized armor, fire immunity, and optional elite variants.

Designed to complement InControl's overworld spawn rules and Majrusz's Difficulty scaling without stacking conflicts.

Features

Core

• Automatic structure detection — All registered structures (vanilla + modded) are runic by default
• Village exclusion — Villages excluded by default (toggle available)
• Structure whitelist/blacklist — Fine-grained control by ID or tag
• Mob whitelist/blacklist — Control which hostile mobs can spawn (45+ bosses blacklisted by default)
• Dimension filtering — Choose which dimensions are affected
• Buffer radius — Expand structure boundaries for spawn detection
• Fully server-side — No client installation required

Spawning

• Initial population — 2-5 mobs spawn throughout a structure the first time it's discovered each session
• Periodic reinforcement — Background spawner maintains mob presence at configurable intervals
• Structure piece-aware — Targets individual rooms and corridors, not the full bounding box
• Column-based floor finding — Efficient vertical scanning for valid spawn positions
• Pack spawning — Mobs spawn in groups matching vanilla biome pack sizes
• Vanilla spawn weights — Respects biome mob probabilities
• Hazard avoidance — Skips lava, water, and rooftop positions
• Difficulty scaling — Spawn cap and interval scale with Easy/Normal/Hard
• Night spawn boost — Configurable faster spawning at night
• Min player distance — Prevents mobs spawning on top of players

Per-Structure Identity

• Structure-aware spawn pipeline — Every spawn path knows which specific structure it's inside
• Per-structure JSON profiles — Override spawn cap, elite chance, armor tiers, weapon pool, shields, enchantment level, and environmental effects per structure
• Progression gating — Per-structure profiles can require a minimum game day (early/mid/late/veteran) before activating
• 238 default profiles across 27 mods (Vanilla, YUNG's, Dungeons Arise, Dungeons and Taverns, Hopo, Moog's, Underground Rooms, Medieval Buildings, Battle Towers, Ice and Fire, Iron's Spellbooks, Ars Nouveau, and more) with individualized settings

Mob Enhancement

• Randomized armor — Configurable tier pool (chainmail through diamond by default) with per-tier drop chance multipliers and custom modded armor set support
• Randomized weapons — Config-driven weapon pool supporting any modded weapon (Spartan Weaponry, Cataclysm Tools, etc.)
• Shield/offhand support (opt-in) — Melee mobs receive shields (Spartan Shields, vanilla shield, or any modded shield)
• Equipment enchantments (opt-in) — Weighted random enchantments (Protection/Blast/Projectile/Thorns on armor, Sharpness/Knockback/Fire Aspect on weapons)
• Fire immunity — Permanent Fire Resistance prevents sunlight burning and also blocks lava/fire attrition when enabled
• Anti-stacking guards — Respects existing armor/weapons from InControl/Majrusz's Difficulty; skips elite buffs on already-buffed mobs
• Elite mobs (opt-in) — Rare enhanced mobs with per-structure custom name prefixes, boosted stats, glow, and bonus XP

Atmospheric Effects (per-structure or global)

• Darkness effect — Pulsing Warden-style vision inside structures
• Mining Fatigue — Slows block-breaking, discourages cheese strategies
• Slowness — Subtle movement penalty that increases danger
• Ambient sounds — Weighted pool of ominous ambient sounds at configurable intervals
• All effects can be enabled/disabled per structure via JSON profiles

Admin Commands

All commands require OP level 2. Available under /runicstructures or the alias /rs.

Command	Description
/rs status	Show mod status and config summary
/rs info	Check if you're inside a runic structure
/rs list	List nearby structures with runic/excluded status and coordinates
/rs reload	Reload structure profiles, invalidate runtime caches, and report validation issues
`/rs debug on	off
/rs spawns	Show spawn statistics
/rs spawns detail	Show per-structure spawn statistics (top 10)
/rs validate	Re-run config validation and report issues

Runecraft Modpack Integration

Runic Structures is the authoritative system for structure-based mob spawning in Runecraft. InControl's structure-specific spawn entries (stronghold sentinels, ancient city guardians, pyramid mimics) have been removed to avoid conflicts — RS handles all structure spawning uniformly.

Compatibility

• InControl — RS owns structure spawning; InControl handles biome, weather, phase, and underground spawning. The two systems are complementary. InControl's global mob enhancements (3% elites, stat boosts) still apply to RS-spawned mobs.
• Majrusz's Difficulty — RS difficulty scaling is gentled (0.8x/1.2x cap, 1.1x/0.85x interval) to avoid stacking with Majrusz's Expert/Master tiers. The eliteMaxBaseHealth threshold prevents RS elite buffs from stacking on mobs already buffed by Majrusz's system.
• Apotheosis — RS's optional enchantment system applies basic enchantments (Protection, Sharpness, Power). Apotheosis's adventure module can further enhance RS-spawned mobs naturally.
• Boss mods — 45+ boss entities blacklisted by default (Cataclysm, BOMD, Mowzie's, Ice & Fire, Stalwart Dungeons, Saints Dragons, Iron's Spellbooks, Ars Nouveau, RealmRPG, Galosphere, Dark Doppelganger, Majrusz's Difficulty).
• Structure mods — Cataclysm arenas, Stalwart Dungeons boss arenas, and BOMD arenas are blacklisted to preserve their scripted encounters. All other structures (DungeonsArise, Yung's, Medieval Buildings, etc.) are runic by default.

Requirements

	Version
Mod	0.9.0
Minecraft	1.20.1
Forge	47.2.0+
Java	17+

Installation

1. Install Minecraft Forge for 1.20.1
2. Download the latest runicstructures-x.x.x.jar from Releases
3. Place the JAR in your mods/ folder
4. Launch the game — config generates on first server start

Configuration

The config file is generated at world/serverconfig/runicstructures-server.toml on first world load.

General

Option	Type	Default	Description
enabled	Boolean	true	Master enable/disable
autoDetectStructures	Boolean	true	Auto-detect all structures. When enabled, whitelists are ignored.
includeVillages	Boolean	false	Include villages when auto-detect is enabled

Structure Filtering

Option	Type	Default	Description
structureWhitelist	List	["minecraft:fortress", ...]	Structure IDs to make runic (manual mode only)
structureTagWhitelist	List	[]	Structure tags to include (manual mode only)
structureBlacklist	List	(see below)	Structure IDs to NEVER make runic (all modes)
structureTagBlacklist	List	[]	Structure tags to NEVER make runic (all modes)

Default structure blacklist: Cataclysm arenas (burning_arena, cursed_pyramid, ruined_citadel, soul_black_smith, sunken_city), Stalwart Dungeons boss arenas (awful_dungeon, nether_dungeon, end_dungeon), BOMD arenas (lich_tower, void_blossom_structure, gauntlet_arena, obsidilith_arena), minecraft:trail_ruins, minecraft:igloo, minecraft:desert_well.

Mob Filtering

Option	Type	Default	Description
mobWhitelist	List	[]	If non-empty, ONLY these mobs spawn. Priority over blacklist.
mobBlacklist	List	(45+ entries)	Mobs to exclude (bosses from 14 mod namespaces)
dimensionSpecificMobs	Boolean	true	Pick mobs from the current biome's spawn list

Other Settings

Option	Type	Default	Description
allowedDimensions	List	["minecraft:overworld", "minecraft:the_nether", "minecraft:the_end", "mining_dimension:mining", "dungeon_realm:dungeon_realm"]	Active dimensions
bufferRadius	Integer (0-16)	0	Extra blocks around structure bounds
debugLogging	Boolean	false	Log each spawn to console

Periodic Spawning

Option	Type	Default	Description
enabled	Boolean	true	Enable periodic forced spawning
spawnInterval	Integer (20-6000)	300	Ticks between spawn attempts
spawnCapPerStructure	Integer (1-64)	6	Max hostile mobs per structure
maxPositionAttempts	Integer (1-20)	10	Position attempts per spawn cycle
minPlayerDistance	Integer (0-48)	6	Min distance from players (initial population ignores this)
chunkSearchRadius	Integer (2-8)	3	Chunk radius to search for structures
randomizeInterval	Boolean	true	Add jitter to prevent synchronized waves
useStructurePieces	Boolean	true	Spawn within individual structure pieces
weightPiecesByArea	Boolean	true	Prefer larger pieces (rooms) for spawning
useVanillaSpawnWeights	Boolean	true	Respect biome spawn weight probabilities (requires dimensionSpecificMobs)
packSpawning	Boolean	true	Spawn mobs in packs
maxPackSize	Integer (1-8)	3	Maximum pack size
scaleCapByStructureSize	Boolean	true	Scale cap by structure footprint area
mobsPerChunkArea	Integer (1-16)	2	Mobs per 16x16 area (when scaling)
maxScaledCap	Integer (1-128)	20	Absolute max cap (when scaling)
fireImmunity	Boolean	true	Grant permanent Fire Resistance
persistentMobs	Boolean	false	Prevent spawned mobs from despawning
nightSpawnMultiplier	Double (1.0-4.0)	1.0	Night spawn rate multiplier
initialPopulationEnabled	Boolean	true	Spawn a group on first discovery
initialPopulationMin	Integer (1-16)	2	Minimum mobs for initial population
initialPopulationMax	Integer (1-32)	5	Maximum mobs for initial population

Armor

Option	Type	Default	Description
armorEnabled	Boolean	true	Equip mod-spawned mobs with randomized armor
armorDropChance	Double (0.0-1.0)	0.05	Drop chance per armor piece on death
allowLeather	Boolean	false	Include leather armor in the pool
allowChainmail	Boolean	true	Include chainmail armor in the pool
allowIron	Boolean	true	Include iron armor in the pool
allowGold	Boolean	true	Include gold armor in the pool
allowDiamond	Boolean	true	Include diamond armor in the pool
allowNetherite	Boolean	false	Include netherite armor in the pool
respectExistingArmor	Boolean	true	Skip armor if mob already has equipment (prevents InControl/Majrusz's stacking)
diamondDropMultiplier	Double (0.0-2.0)	0.5	Drop chance multiplier for diamond armor
netheriteDropMultiplier	Double (0.0-2.0)	0.25	Drop chance multiplier for netherite armor

Weapons

Option	Type	Default	Description
weaponsEnabled	Boolean	false	Equip melee mobs with random swords (skeletons excluded)
weaponDropChance	Double (0.0-1.0)	0.05	Weapon drop chance on death
respectExistingWeapon	Boolean	true	Skip weapon if mob already has a mainhand item

Enchantments

Option	Type	Default	Description
enchantmentsEnabled	Boolean	false	Apply random enchantments to mod-applied equipment
maxEnchantmentLevel	Integer (1-5)	2	Maximum enchantment level

Equipment Pools

Option	Type	Default	Description
weaponPool	List	[]	Custom weapon items (replaces hardcoded swords when non-empty)
customArmorSets	List	[]	Custom armor sets: "name=helmet,chest,legs,boots"
shieldsEnabled	Boolean	false	Enable offhand shield equipment
shieldPool	List	["minecraft:shield"]	Shield items for offhand
shieldChance	Double (0.0-1.0)	0.2	Chance for melee mobs to receive a shield
progressionScalingEnabled	Boolean	false	Enable day-count-based profile progression gating

Per-Structure Profiles

Per-structure overrides are defined in serverconfig/runicstructures-structures.json. Each structure ID maps to an override object. Any field omitted uses the global TOML config value.

Available override fields: spawnCap, eliteChance, eliteNamePrefix, persistentMobs, armorTiers, weaponPool, shieldChance, shieldPool, enchantmentLevel, darkness, miningFatigue, slowness, ambientSounds, progressionTier.

Difficulty Scaling

Option	Type	Default	Description
enabled	Boolean	true	Enable difficulty-based scaling
easyCapMultiplier	Double (0.1-4.0)	0.5	Cap multiplier on Easy
normalCapMultiplier	Double (0.1-4.0)	0.8	Cap multiplier on Normal
hardCapMultiplier	Double (0.1-4.0)	1.2	Cap multiplier on Hard
easyIntervalMultiplier	Double (0.25-4.0)	1.5	Interval multiplier on Easy (higher = slower)
normalIntervalMultiplier	Double (0.25-4.0)	1.1	Interval multiplier on Normal
hardIntervalMultiplier	Double (0.25-4.0)	0.85	Interval multiplier on Hard (lower = faster)

Environmental Effects

Option	Type	Default	Description
applyDarknessEffect	Boolean	false	Apply Darkness effect to players in structures
darknessAmplifier	Integer (0-4)	0	Darkness effect amplifier level
applyMiningFatigue	Boolean	false	Apply Mining Fatigue to players in structures
miningFatigueAmplifier	Integer (0-4)	0	Mining Fatigue amplifier level
applySlowness	Boolean	false	Apply Slowness to players in structures
slownessAmplifier	Integer (0-4)	0	Slowness amplifier level
playAmbientSounds	Boolean	false	Play ominous ambient sounds in structures
ambientSoundInterval	Integer (40-2400)	400	Ticks between ambient sounds

Elite Spawns

Option	Type	Default	Description
enabled	Boolean	false	Enable rare elite mob spawns
spawnChance	Double (0.0-1.0)	0.02	Chance for each spawn to be elite
healthMultiplier	Double (1.0-10.0)	2.5	Elite health multiplier
damageMultiplier	Double (1.0-10.0)	1.75	Elite damage multiplier
glowingEffect	Boolean	true	Elite mobs glow through walls
namePrefix	String	"Runic"	Custom name prefix for elite mobs
bonusXP	Integer (0-500)	30	Bonus XP when an elite is killed by a player
maxBaseHealth	Double (0.0-1000.0)	40.0	Skip elite buffs if mob's base health exceeds this (0 = disabled)

API

Other mods can interact with Runic Structures via RunicStructuresAPI:

import com.otectus.runicstructures.api.RunicStructuresAPI;

// Register a structure as runic
RunicStructuresAPI.registerRunicStructure(new ResourceLocation("mymod", "my_dungeon"));

// Check if a position is runic
boolean runic = RunicStructuresAPI.isPositionRunic(serverLevel, blockPos);

// Unregister
RunicStructuresAPI.unregisterRunicStructure(new ResourceLocation("mymod", "my_dungeon"));

How It Works

The mod uses three complementary mechanisms:

1. Initial population — When a structure is first discovered each session, 2-5 mobs are immediately spawned throughout its rooms and corridors. Uses aggressive position-finding (50 scan attempts) with distributed placement across structure pieces.

2. Spawn event interception — Hooks into Forge's MobSpawnEvent.SpawnPlacementCheck and MobSpawnEvent.PositionCheck to force-allow hostile mob spawns inside runic structures, bypassing light level and time-of-day checks.

3. Periodic spawning — A server tick handler maintains mob presence inside structures at configurable intervals. Uses structure piece-aware targeting, column-based floor finding, pack spawning, and hazard avoidance.

All mod-spawned mobs — regardless of spawn path — receive the full enhancement pipeline: elite roll, armor, weapons, enchantments, and Fire Resistance (each gated by config). Structure detection uses Minecraft's StructureManager with a per-chunk cache and fast-reject gate (hasAnyStructureAt) for efficient lookups.

Building from Source

git clone https://github.com/Otectus/Runic-Structures.git
cd Runic-Structures
./gradlew build

The built JAR will be in build/libs/.

License

This project is licensed under the GNU General Public License v3.0.