Custom Mods

Custom Mods

These mods are built from source or bytecode-patched in-house. They are committed directly to the repo, in mods/ of all three distributions, and each has a packwiz metafile like any other mod (for all but OfflineSkins it downloads the committed copy). custom_jars_manifest.json lists every one of them with its SHA-256 and size, and the stale-jar cleanup keeps what it lists and replaces a copy whose checksum differs. (Older hand-kept lists of these jars remain in sync_from_repo.bat and, as a fallback, in the cleanup script; iridescentserver.bat no longer has one and runs that script.)

JVM flag requirement: the two bytecode-patched mods (Patchouli, Ars Nouveau) create dead code paths that the verifier rejects, so the client and the server JVM args both need -noverify. The server has it built into iridescentserver.bat; on the client you add it by hand in PrismLauncher (Instance → Settings → Java → JVM arguments).

---

In-house mods (built from source)

iridescent_origins-1.0.0.jar

The Origins / races / classes implementation. On first join the player answers three prompts in order: Origin (13 origins, 9 vanilla + 4 custom) → Race (11 icraft) → Class (13 icraft). The jar implements the glass-cannon HP modifiers, the Faefolk armor weakness, Witch of Ink frailty, the Archmage glass frame and all the per-class power JSONs.

Source: iridescent-origins-mod/src/main/resources/data/icraft/origins/*.json Build: bash ./build_mod.sh in iridescent-origins-mod/, run in WSL (about 40 s; it builds the jar and deploys it to the three distros). Or jar surgery for content-only edits (extract the content of iridescent_origins-1.0.0.jar, edit it, re-zip it), with no Gradle rebuild.

iridescent_biomes-1.0.0.jar

Custom TerraBlender region registration for iridescent_biomes:cherry_river_valley and iridescent_biomes:cherry_mountains. TerraBlender 3.x on 1.20.1 needs the region registered on the Java side through explicit Climate.ParameterPoints, because datapacks alone can't assign parameter points. The biome JSONs, the is_overworld and is_mountain tags and the lang entries ship inside the jar under data/iridescent_biomes/... (the biome namespace MUST match the modId).

Source: iridescent-biomes-mod/src/main/... Build: bash ./build_mod.sh in iridescent-biomes-mod/, run in WSL like the origins build (ForgeGradle; host Gradle no longer works, and this build has not been run since). Caveat: if you delete this jar, the biomes stop spawning but stay registered (Nature's Compass shows them with an empty Dimension).

iridescent_codex_data.jar

The Patchouli Codex book, shipped as a javafml content mod with a minimal compiled @Mod class. modId MUST be "icraft" to match the book.json path at data/icraft/patchouli_books/iridescent_codex/book.json. Patchouli's BookRegistry.init() scans data/{modId}/patchouli_books/, so with a mismatched modId the book is silently never registered (confirmed 2026-04-19: earlier attempts with modId iridescent_codex_data produced "Invalid book" tooltips).

Source: datapack_sources/iridescent_codex/

• src/com/iridescentcraft/codex/IridescentCodex.java: the @Mod("icraft") entrypoint
• stub/net/minecraftforge/fml/common/Mod.java: an annotation stub so the class compiles without the Forge jar
• Only IridescentCodex.class ends up in the final jar
• data/ mirrors to assets/ automatically because book.json has use_resource_pack: true

Build: python .minecraft/dev/codex/codex.py release builds the jar from the book source (filling its facts from the registries and scripts), checks that every page fits, and writes the three distros, the three manifests and markers and expected_state.json; commit what it lists. build_codex.sh is needed only when the Java class changes. The pre-push hook and CI fail while the committed jar is stale (.minecraft/dev/codex/README.md).

iridescent_tetra_expansion-1.0.0.jar (Modular Spells + Reforging bundle)

Added 2026-04-26 (as iridescent_modular_spells); bundled into iridescent_tetra_expansion-1.0.0.jar on 2026-05-01. The jar ships two [[mods]] from one file: iridescent_modular_spells (below) and iridescent_reforging (the modular-armor extension). Item IDs keep their original namespaces (iridescent_modular_spells: / iridescent_reforging:); the full mod-ID merge into a single iridescent_tetra_expansion namespace is deferred to the alpha→beta cutover (Option C). The standalone iridescent_modular_spells-0.2.0.jar and iridescent_reforging jars are superseded.

Modular Spells is a modular spell book mod for both the ISS and the Ars Nouveau ecosystems, with full Tetra workbench integration. It is a license-clean reimplementation of CurseForge's TSB: TSB is All Rights Reserved, so we mirror its API-driven structure but write our own code and data.

Books (15 modular variants):

Variant	Tier	Inherits from	Slot count	Source
modular_copper_spell_book	T1	ISS SpellBook	5	crafted (vanilla → modular auto-convert)
modular_iron_spell_book	T2	ISS SpellBook	10	crafted
modular_gold_spell_book	T2	ISS SpellBook	10	crafted
modular_druidic_spell_book	T2	ISS SpellBook	10	rare world loot
modular_villager_spell_book	T2	ISS SpellBook	8	cleric trade
modular_rotten_spell_book	T2	ISS SpellBook	8	rare world loot (-15% spell_resist trade-off)
modular_diamond_spell_book	T3	ISS SpellBook	15	crafted
modular_dragonskin_spell_book	T3	ISS SpellBook	12	crafted from Ender Dragon dragonskin
modular_blaze_spell_book	T3	ISS SpellBook	12	first-kill: ISS fire_boss (then 50% sustained from blaze drop)
modular_evoker_spell_book	T3	ISS SpellBook	12	first-kill: ISS archevoker
modular_netherite_spell_book	T4	ISS SpellBook	15	smithing
modular_necronomicon_spell_book	T4	ISS SpellBook	15	first-kill: ISS dead_king
modular_novice_spell_book	T1	Ars SpellBook (Tier ONE)	per Ars	craft / vanilla → modular auto-convert
modular_apprentice_spell_book	T2	Ars SpellBook (Tier TWO)	per Ars	craft
modular_archmage_spell_book	T3	Ars SpellBook (Tier THREE)	per Ars	craft

Per-book intrinsic stat overlay (BookKind enum): each item adds Phase 6F buff modifiers on top of ISS's vanilla intrinsics. Stats stack additively across 3 layers in getAttributeModifiers(SlotContext, UUID, ItemStack):

1. super: ISS vanilla per-book intrinsics (preserved)
2. BookKind.intrinsicModifiers: the Phase 6F overlay (e.g. dragonskin: +25% Ender and +50 max_mana on top of ISS's +10% Ender, for a +35% Ender baseline)
3. getAttributeModifiersCached: Tetra slot/lining attributes from the installed modules

The mage power curve is back-loaded by design: mages are weak early and reach the highest peaks at T3-T4. The Tetra modules of a book add a fixed bonus whatever they are made of (since 2026-10-19; Tetra materials 2f).

Tetra slot model (4 majors per book, no core slot; items are tier-locked):

• ISS: iss_book/{front_cover, back_cover, spine, pages}
• Ars: ars_book/{front_cover, back_cover, spine, dye}
• The front and back covers each have a separate lining install (Tetra-canonical displayType: improvement), with fabric/fibre/skin lining categories that give thematic stat bonuses.

Tetra replacement system: vanilla irons_spellbooks:<X>_spell_book and ars_nouveau:<X>_spell_book items auto-convert to our modular variants on their first inventory tick, with default modules pre-installed, so the vanilla loot tables need no rewrite.

ISS boss-drop wiring (Phase 6F-1):

• First-kill guarantees (per player, EntityEvents.death + persistentData): dead_king → necronomicon, archevoker → evoker_spell_book, fire_boss → blaze_spell_book, aether:valkyrie_queen → magehunter
• Sustained drops (LootJS): dead_king → blood_staff 50%, citadel_keeper → keeper_flamberge 40%, ISS cryomancer mob → ice_staff 15%, ISS pyromancer mob → pyromancer armor pieces ~10% each, aether:cockatrice → lightning_rod 25%, twilight:snow_queen → ice_staff 50%, twilight:alpha_yeti → ice_staff 25%, aether:valkyrie_queen → magehunter 30%, vanilla phantom (during a thunderstorm) → lightning_rod 5%

The legacy imodspells_slots NBT system (Phase 1-5) is still active for stat-bonus computation through Phase 6C. Phase 6D will run the migration to Tetra Modules NBT and retire AttributeApplier + AnvilModuleInstaller.

Cover materials (ISS metal): leather (T1) → copper (T1) → iron (T2) → gold (T2) → diamond (T3) → netherite (T4) Cover materials (Ars cloth): white_wool (T1) → manaweave_cloth (T2 Botania) → sorcerer_robes (T3 Ars) → spell_cloth (T4 Botania endgame)

Custom enchants (book-exclusive via custom EnchantmentCategory):

• mana_capacity I-V: +5%/lv max mana (ISS + Ars)
• mana_flow I-III: +5%/lv mana regen
• magic_crit_chance I-III: +5%/lv magic crit roll
• magic_crit_damage I-III: +25%/lv magic crit damage

Magic crit hook: vanilla magic doesn't crit. kubejs/server_scripts/magic_crit_hook.js intercepts a magic-typed LivingHurtEvent, rolls the magic_crit_chance enchant on the attacker's mainhand book plus the player's icraft_crit_chance attribute (the same attribute melee crit uses), and multiplies the damage on a hit.

Caster starter kits: Archmage / Battlemage / Void Summoner spawn with the modular variants instead of vanilla ISS/Ars books.

Source: iridescent-tetra-expansion-mod/src/main/... (the consolidated project; the legacy iridescent-modular-spells-mod/ + iridescent-reforging-mod/ trees are superseded). Build: bash iridescent-tetra-expansion-mod/wsl-build.sh (Gradle wrapper; builds the bundled iridescent_tetra_expansion-1.0.0.jar and deploys to all 3 distros). The per-mod build_mod.sh scripts are stale. Build deps: ISS, Curios, Ars Nouveau and GeckoLib (transitive, because Ars's SpellBook implements GeoItem), plus Tetra/Geckolib for the Reforging half; all are compileOnly via flatDir libs/.

mek_walkable_cables-1.0.1.jar

A Mekanism coremod that makes cables walkable instead of letting players pass through them.

zeta_racefix-1.0.0.jar

Race selection fix for the Origins layer ordering bug. The pack does not ship this jar: it is in no mod index, no mods folder and not in the custom-jar manifest (only old hand-kept lists in a few scripts still name it).

offlineskins-1.20.1-v1.jar

Offline skin support, required for LAN play without Mojang auth.

iridescent_difficulty-0.1.0.jar

Added 2026-05-03. Bespoke time-based per-dimension mob scaling. It replaces ScalingMobs / ImprovedMobs / AzukaarsFairDifficultyOverhaul (removed) and the dimension-scaling block of mob_scaling_unified.js (the tier-HP block stays as a static composable rule). Majrusz's Difficulty stays loaded for its treasure bags and content additions, but its scaling is disabled in config.

Tier curves (all configurable in config/iridescent_difficulty-common.toml):

Tier	Dimensions	Start %	Cap %	Cap Hours
T1	Overworld	150%	300%	100
T2	Twilight Forest, Blue Skies (Everbright, Everdawn), the Abyss's pocket dimension	200%	350%	100
T3	Undergarden, Deeper Darker, Nether, Abyss + its Frost World	300%	450%	100
T4	The End, Aether (Deep Aether's biomes included), the Ad Astra planets and orbits, Iron's Spellbooks' pocket dimension, the Reality Marble	600%	1000%	200

Dimensions are matched by exact id, and any dimension not listed uses the T1 curve. Deep Aether has no dimension of its own (its biomes are part of the Aether), so it follows the Aether: T4 since 2026-10-16 (T2 before). /icraftdiff status all shows the tier each dimension resolved to.

Multiplier scope: linear on max_health / attack_damage / armor; sqrt on movement_speed (so a 6× HP mob isn't also 6× as fast). Tamed mobs and mobs outside the MONSTER category are skipped, except the mobs on a configurable force-scale list; since 2026-10-16 that list includes the Aether's own hostile creatures (blue and golden swets, whirlwinds and evil whirlwinds, the aechor plant, cockatrices, zephyrs, and Deep Aether's baby zephyrs and venomites). Bosses are skipped only when they are on the configurable excluded-entities list; there is no automatic boss detection. Since 2026-10-16 the tier lists and that list are generated from the pack's boss and dimension registries: every boss with a designed health or the boss x3 is excluded (78 entity ids), and every tiered dimension is on its tier's list (the planets, orbits and pocket dimensions ran the T1 curve before).

End uncap: killing the Ender Dragon in-world removes the cap for any dimension in the uncapAfterEnderDragon list (default: just minecraft:the_end). The multiplier then extrapolates proportionally beyond the cap once capHours has passed.

Idle gating: the per-dim timer ticks at the active / total ratio of players in that dim. A player counts as idle if either of these holds:

• No movement (>0.1 blocks delta) or damage taken/dealt for idleThresholdMinutes (default 5)
• Within spawnIdleRadius blocks (chebyshev cube, default 10) of their respawn point (the bed if set, otherwise world spawn)

So with 4 players, 2 active and 2 idle, the tick rate is 50%; with 7 players and 3 active it is ~42.86%; an empty dim ticks at 0%. A fractional tickAccumulator on DimensionDifficultyData implements this.

Op-only debug commands (permission level 2):

• /icraftdiff status [all]: status of the current dim or of all dims (tier, hours/capHours, multiplier, rate, active/total split, ED-killed flag)
• /icraftdiff timer set <hours>: seek the current dim's timer (QA)
• /icraftdiff timer reset: zero the current dim's timer
• /icraftdiff uncap end: set the ED-killed flag for the End by hand (to test the uncap)
• /icraftdiff players: three-state per-player status (✓ active / ◍ at-spawn / ✗ idle) with idle minutes

Source: iridescent-difficulty-mod/ Build: bash iridescent-difficulty-mod/wsl-build.sh (ForgeGradle in WSL, no mixin; deploys to all 3 distros) Stacks on top of (not replaced): per-kill boss scaling, per player (boss_progressive.js; vanilla bosses do not scale per kill), mob_scaling_unified.js tier-HP block (basic 3× / mid 1.5× / champion 1.25×), Majrusz content features (treasure bags + spawn variants).

iridescent_relics-1.0.0.jar

The pack's relics: boss-reward artifacts (the Relic of the Remnant and others), built as an addon of the Relics framework with its leveling, ability and style system.

Source: iridescent-relics-mod/ Build: bash iridescent-relics-mod/wsl-build.sh

iridescent_grand_compass-1.0.0.jar

One gold Grand Compass that finds boss arenas, structures (through Explorer's Compass) and biomes (through Nature's Compass), opening those mods' own search screens.

Source: iridescent-grand-compass-mod/ Build: bash iridescent-grand-compass-mod/wsl-build.sh

iridescent_durability_clamp-0.1.0.jar

A mixin mod: an item never breaks from durability damage. ItemStack.hurtAndBreak is clamped so the item stops one point short of breaking, the pattern Tetra uses for its own items, applied to every item that takes damage the vanilla way. kubejs/server_scripts/death_penalty.js decides what an item at that point can still do.

Source: iridescent-durability-clamp/ Build: bash iridescent-durability-clamp/wsl-build.sh

Managed forks (upstream source, our changes)

justlevelingfork-1.2.1-iridescent.1.jar (Iridescent Aptitudes)

A fork of JustLeveling-Fork (Apache 2.0): the aptitude and skill leveling system. The pack's version remaps passives (Magic Resist to DEF, Beneficial Effect to INT), strips the mod's own skill effects (KubeJS handles the gameplay) and sets skill thresholds at levels 5, 10, 15, 20 and 30. The modid stays justlevelingfork, so saved aptitude data carries over.

Source: iridescent-aptitudes-mod/ Build: bash iridescent-aptitudes-mod/wsl-build.sh

linearxp-1.0.0-iridescent.1.jar (Linear Experience)

A fork of Linear Experience, which replaces vanilla's experience curve with configurable calculation modes.

Source: linear-experience-mod/ Build: bash linear-experience-mod/wsl-build.sh

lovely_sparkle_pieces-0.1.0.0-iridescent.2.jar (Iridescent Lovely Pieces)

A fork of Lovely Sparkle Pieces (its 1.20.1 Forge branch, used with the author's permission for non-commercial modpacks): about 60 Curios accessories and the Gambler set bonus. The modid stays lovely_sparkle_pieces. The pack's changes fix a damage attribute that zeroed melee damage without one of its curios, turn off the Blasphemous Contract's automatic grant, make the Adventurer's Belt modifiers temporary, remove the client-FPS-based item, the heart-rate HUD and the damage-number particles, and remove every crafting recipe: the items come only from the pack's loot.

Source: iridescent-lovely-pieces-mod/ Build: bash iridescent-lovely-pieces-mod/wsl-build.sh

---

Bytecode-patched mods (not in-house source)

Patchouli-1.20.1-85-FORGE.jar

Bytecode-patched: athrow→pop in Book.class disables the use_resource_pack enforcement, which crashes when the book.json's resource pack flag conflicts with our pack setup. Without the patch, the codex book throws on registration.

class-artifacts-forge-2.0.5.jar (Epic RPG: Class Artifacts)

Bytecode-patched: the inventory "Sets" button moves from its hardcoded place on top of the vanilla recipe-book button to just right of it, re-anchored every frame.

ars_nouveau-1.20.1-4.12.7-all.jar

Bytecode-patched: doApply→immediate return in DungeonLootEnhancerModifier.class disables Ars's chest loot injection. Without the patch, Ars adds glyph items to vanilla dungeon chests and bypasses the enchanted-book and spell-book progression curve of our LootJS overhaul.

---

Adding a new custom JAR

1. Add the JAR to mods/ in all three distributions (main, server_distribution, distribution/client) and commit the three copies (a mod with a wsl-build.sh deploys them itself; mods/*.jar is git-ignored, so the jars are force-added)
2. Run regen_custom_jars_manifest.ps1: it writes the jar's SHA-256 and size into the three custom_jars_manifest.json files and points the jar's metafile at the committed copy (a new jar needs a line in sync_custom_jar_markers.py first)
3. Regenerate the indexes and the two expected_state.json files, and commit them with the jar
4. Give the mod an intake record with intake.py: the pre-push hook refuses a mod without one
5. If it is bytecode-patched, add a -noverify requirement note here

A rebuild under the same file name needs step 2 again (and the files it changes committed), because the jar's checksum changes. If the jar is mostly content (assets/data/lang) with no compiled changes, jar surgery (extract → edit → re-zip → keep the filename) avoids the Gradle rebuild and changes no file name, but it needs step 2 as well.

---

Related

• Iridescent Modular Spells design doc
• Mod overview