Introduction

Arbitrary Alloy is a realistic metallurgy mod for Minecraft 1.12.2 Forge. It removes vanilla iron/gold tools, ingots, nuggets, and blocks, replacing them with a composition-based alloy system: mine real-world metal ores, control carbon content through smelting, blend different compositions on a crafting table, and craft tools whose stats are dynamically determined by their metal composition — all while watching them slowly corrode over time.

Core Gameplay

Mine → Smelt (carbon ingot) → Re-smelt (decarburize) → Blend (average) → Craft tool → Corrode

Stage	Description
Mining	12 real-world metal ores (Cu, Sn, Zn, Pb, Ni, Ag, Al, Mn, Cr, Ti, W, Pt) + vanilla iron/gold ores
Smelting	Smelt any metal ore → metal ingot with ~93-97% metal + 3-7% random carbon
Decarb	Put a carbon-containing ingot back in the furnace → reduced carbon by 20%-50% (hacks furnace input slot NBT.Therefore, unknown alloy ingots may appear when only one metal ingot is fired.)
Blending	2-4 ingots of any composition in shapeless crafting → same count, averaged composition
Tools	2-3 same-composition ingots + sticks → Sword/Pickaxe/Axe/Shovel/Hoe with dynamic stats
Corrosion	Tools lose durability over time; accelerated in water (×2), rain (×1.5), humid biomes (×1.3)

Removed Vanilla Content

All iron/gold tools, ingots, nuggets, blocks, armor, horse armor, iron doors, and their crafting/furnace recipes.

Configuration

Config file: .minecraft/config/arbitraryalloy.cfg

Category	Key	Default	Description
Carbon	`carbonInitialMin`	0.03	Minimum carbon from ore smelting
Carbon	`carbonInitialMax`	0.07	Maximum carbon from ore smelting
Carbon	`carbonReductionMin`	0.20	Minimum carbon reduction per re-smelt
Carbon	`carbonReductionMax`	0.50	Maximum carbon reduction per re-smelt
Corrosion	`corrosionInterval`	1200	Ticks between corrosion checks (60s)
Corrosion	`corrosionChance`	0.05	Base chance of durability loss per check
OreGen	`oreCountCopper` ~ `oreCountPlatinum`	varies	Veins per chunk for each ore
OreGen	`oreVeinSize`	8	Maximum vein size
Tools	`baseDurabilityIron`	250	Base durability
Tools	`baseSpeedIron`	6.0	Base mining speed
Tools	`baseDamageIron`	2.0	Base attack damage
Tools	`baseEnchantabilityIron`	14	Base enchantability