Black Market

#1. Goal

The black market turns the mod's final produce into basic resources and materials. A player who specializes in cultivation can then progress in the rest of a modpack without mining everything.

Design goals:

1. Complexity pays. The more processing steps, time and skill a product needs, the more it's worth. A cured bud is worth twice a dried one, and a concentrate several iron ingots.
2. Quality pays. Better soil and genetics raise the price. Living soil (quality cap 100 %) outsells mineral fertilizer (cap ~80 %) per item, while mineral wins on volume.
3. No infinite money. Market saturation, a buy/sell spread and the absence of buy-back loops keep it from replacing every other way of getting resources.
4. Modpack-friendly. Every price and offer is data-driven, modded resources come in through conventional tags, and the currency can be swapped for Numismatics, Lightman's Currency or emeralds.
5. Server-ready. One shared market per world, per-player reputation, nothing client-authoritative.

#2. How players use it

grow → process → (cure / extract) ──sell──▶ Dealer ──cash──▶ buy basic resources & materials
                                         ▲                    (iron, coal, redstone, glass, …)
                     reputation ─────────┘──▶ unlocks better offers, prices, contracts

The black market screen has three tabs:

• Sell: put produce in the slot and see the live price (value × quality × demand × daily factor × reputation). It shows the reason for the price ("market flooded", "hot today").
• Buy: the offer list, filtered by your reputation tier, with stock and restock timer.
• Contracts: the Dealer's current requests (see §7).

#3. Value model

All prices use one unit, credits (₡). 1 ₡ ≈ 1/10 iron ingot.

#3.1 Produce value from complexity

Every sellable item has a market value, derived automatically from the recipe graph, like an EMC mapper:

value(product) = (Σ value(inputs) + minutes_of_processing × 0.5 ₡) × tier_markup

• Raw harvest values are set per plant and reflect how hard the plant is to grow: altitude for coca, cuttings and shade for salvia, the sterile chain for mushrooms, foraging for semilanceata.
• Processing time is real time at 20 TPS. A curing jar holds 16 buds for ~60 minutes, which is 3.75 minutes per bud.
• Pack devs can override any value with a datapack. Derived values update automatically.

#3.2 Quality

sale price × (0.5 + quality), so 0 % pays ×0.5, 50 % pays ×1.0, 80 % (mineral cap) pays ×1.3 and 100 % (living soil) pays ×1.5. Khat additionally scales with freshness (wilted khat pays ~25 %).

#3.3 Produce values (base, before market effects)

Only products that exist in the mod are listed:

Notes:

• Datura is deliberately nearly worthless ("nobody wants that"). The Dealer buys only the poison, cheaply.
• Fresh produce sells (it's T0) but loses the T1+ markup, so drying is always worth it.
• Rough feel at Tier 0 reputation: one cannabis plant (~3 buds, dried, 50 % quality) ≈ 0.7 iron ingot. Cured at 80 % quality ≈ 1.8 iron ingots per plant. A 20× salvia extract ≈ 7 iron ingots.

#4. Offers: basic resources

#4.1 Pricing anchor

Basic resource values blend two references:

• ProjectE default EMC for scarcity: cobblestone 1, iron ingot 256, gold ingot 2048, diamond 8192, emerald 16384 (ModdedMC wiki).
• Vanilla villager exchange rates for everyday value: e.g. 20 wheat, 4 iron ingots, 3 gold ingots, 15 coal or 1 diamond buy one emerald (Minecraft Wiki: Trading).

Where they disagree, the value sits in between:

• Gold: ProjectE says 8 iron, villagers say 1.3 iron → 1.5 iron, because gold farms are common in modern packs.
• Diamond: ProjectE says 32 iron, villagers say 4 → 12 iron.
• Wheat: villagers overpay for it; it's renewable → 1/25 iron.

#4.2 Default offer list

The Dealer sells at value × (1.25 − 0.05 × reputation tier), so the spread is 25 % at tier 0 and 5 % at tier 4. Prices below are at tier 0. Bundles keep prices round.

Modded resources: the default datapack also ships tag offers. They stay hidden while the conventional tag is empty; once a mod fills it, the Dealer sells the first item of the tag. A modpack with tin, lead, silver, nickel, zinc, osmium, uranium or aluminium gets those offers automatically. (NeoForge does not allow tag conditions in datapack registries, which load before tags, so the check happens at runtime.)

Pack devs change everything through data/<ns>/plantations/black_market/offer/*.json or KubeJS.

#4.3 Stock

Each offer has a stock per restock (e.g. iron: 4 bundles) that refills every in-game morning. Stock is per player by default (config: shared on a server).

#5. Market dynamics

Anti-exploit rules (checked by tests):

• The Dealer never buys anything it sells, and never sells processed produce.
• No offer plus processing chain may produce sellable value faster than growing does. In particular, bone meal on drug plants only advances one stage (config), so "buy bone meal → instant buds → sell" can't outrun saturation.
• Prices floor at 25 % of value, so nothing hits zero, and saturation recovers on its own.

#6. Reputation

Every ₡ of value sold earns reputation XP. Reputation is per player (data attachment).

Failing contracts or getting caught in a raid (see §8) costs reputation.

Each tier has an advancement in the Black Market tab, with the first sale as its root. They use the criterion plantations:reputation_tier ({"tier": 0-4}), which packs and quest mods can use too. It is checked whenever reputation changes and on login.

#7. Contracts

The Dealer offers 1–3 contracts per in-game day (one, two from Trusted, three at Kingpin); each template has a minimum tier:

"Bring me 16 cured buds, quality ≥ 70 %, within 3 days." → reward ₡ × 1.4 + reputation, sometimes an item (strain seeds, a rare offer unlock).

Contracts are generated from data (plantations:black_market/contract_template) and give goals beyond "sell more". They also reward the quality systems and work as quest hooks for FTB Quests.

#8. Heat (optional)

Config blackMarket.heat: off / light (default) / full.

• Heat rises with sales, phone calls and large produce stashes near your base. It decays over time.
• light: high heat only means the Dealer avoids you (the phone fails) and prices drop by up to 20 %.
• full: at maximum heat an enforcer patrol (pillager-style mobs) can raid. They target drying racks, curing jars and stashes. Beating them clears heat; losing costs reputation and some produce.

#9. Currency

Physical cash, so it works with storage, automation and player trading:

• Payouts always use the largest notes, so there's no need to craft notes up (10 items don't fit a crafting grid anyway).
• Fractional amounts (sales are not whole numbers) go onto the player's ledger balance at the Dealer and are paid out once they add up to whole banknotes.
• Config blackMarket.currency:
  • plantations (default): the cash items above
  • emerald: 1 emerald = 40 ₡, the villager-rate anchor
  • numismatics: Create: Numismatics coins, 1 spur = 1 ₡ (bevel 8, sprocket 16, cog 64, crown 512, sun 4096)
  • lightmans: Lightman's Currency coins, 1 copper coin = 1 ₡ (×10 per step up to netherite)
  • custom: any items with credit values from customCurrency
  • Coins are plain items, so none of this needs a compile-time dependency. The two coin modes fall back to plantations while their mod is missing.

#10. Integration

Details and tests: INTEGRATIONS.md.