Source of truth for Medici (medici), a Venetian-banking economy mod for All the Mods 10 (NeoForge 1.21.1). Every GitHub issue links back to a section here. If an issue and this doc disagree, fix the doc first. Economy numbers live in ECONOMY.md; this doc says what and why.

Status: draft v3 · 2026-11-04 · mod list checked against the local ATM10 8.4 instance (Prism, NeoForge 21.1.x) Changes in v3: the Artist and the Arts (§4.9); the Venetian building set replaces the small decor list (§4.8). Changes in v2: every name is English (penny, groat, ducat, mint press, coin purse, bank counter, vending machine, coin slot, turnstile, ticket gate, the Merchant, the Banker); only well-known words stay Italian (Rialto, Medici, gondola, terrazzo, Doge). Added found money: mob drops and chest loot (§4.7).

1. Goal

Make trading between players the most fun thing to build on an ATM10 server.

ATM10 players end up rich in everything and poor in reasons to talk to each other. Medici gives them a shared money, physical and Venetian: copper pennies, silver groats, gold ducats, carried in a purse, struck at a powered mint, kept in a bank, spent at vending machines and at coin locks, turnstiles and ticket gates that open doors, rooms, inventories and rides. Players become merchants, bankers, landlords and showmen; the town becomes the Rialto.

Light but fun means:

1.1 Players we design for

• The merchant: automates a farm, sells its output from a row of vending machines in the market square.
• The banker: runs the town's bank, changes money, sends transfers, sells letters of exchange.
• The showman: builds a Create ride, a maze, a parkour tower or a museum and sells tickets at a turnstile.
• The landlord: rents a shop stall or a locked storage room by the day.
• The newcomer: has no mint and no farm yet; earns first coins from the Merchant (§4.6), from pillagers' purses and from coins found in chests and ruins (§4.7), and spends them in other players' shops instead of grinding everything alone.
• The patron: has made it and wants the world to know: commissions a portrait in front of the Rialto, a marble bust for the bank hall, a ceiling fresco for the trading house, a crest for the team (§4.9).
• The adventurer: raids outposts, shipwrecks, bastions and boss lairs and comes home with ducats and antique coins to sell or appraise.

1.2 Non-goals

No gambling (no slot machines or loot boxes paying out coins; the Artist's chance only varies what you get within what you paid for, §4.9.1), no real-money hooks, no player-to-player loans or interest (§3.3 has a joke about that), no new claim system, no global auction house GUI.

2. Target and fit

• Minecraft 1.21.1, NeoForge 21.1, Java 21. Target pack: ATM10 (local instance 8.4). Works in any 1.21.1 pack; every integration is optional.
• No economy mod in ATM10: neither Lightman's Currency nor Create: Numismatics ships in ATM10 8.4. Medici fills that gap instead of competing with one. If a pack adds Lightman's or Numismatics anyway, Medici coins stay separate items; KubeJS can add exchange recipes (modpack-devs).

2.1 ATM10 mods we build on (all present in 8.4)

3. Identity

3.1 Name and premise

Medici. The Florentine Medici Bank ran a branch in Venice from the early 1400s; our mod is that branch, opened on your server's Rialto, run by the players. Tagline: "Coin, counter, ticket."

3.2 Look

Venice around 1500, with machines that work: Istrian stone and terrazzo, Venetian red plaster, walnut counters, crimson velvet, gold-leaf mosaic, verdigris copper, lagoon teal glass. The machines are brass and enamel with glowing coin slots: a Renaissance bank that got electricity and never told anyone.

Motifs (all our own drawings): the winged lion of St Mark on its column as the mod emblem, the gondola prow, the lion also as a historical motif on the ducat, coin stacks, scales, abacus beads, wax seals, ledgers ruled in red.

3.3 Tone

Warm, mercantile, a little pompous. Item tooltips read like a ledger ("Debit: 3 groats"). The bank refuses to pay interest because the Church frowns on usury; the guidebook explains the workaround Venetians used (the bill of exchange) and that's how the letter of exchange works.

3.4 IP guardrails

• History is public: mint, ducat, groat, penny, Rialto, transfer, Pacioli, the gondola prow, the winged lion as a motif.
• No names, art, sounds or logos from other mods (Lightman's Currency, Numismatics), games (Assassin's Creed II's Venice, The Merchant of Venice adaptations) or real banks. The Medici palle coat of arms is not used as the logo.
• No gambling mechanics; nothing that mocks real groups.

4. Content

Light: 22 gameplay items and blocks for v1.0, plus the Venetian building set (§4.8) and the Arts (§4.9). Each entry: what it does, how it chains.

4.1 Coins

Decimal on purpose: prices read 1D 4G 5P or 145 p, the GUI always shows both. Coins stack to 64, are tagged medici:coins and c:coins, have a value component read by every Medici block (so packs can add coins by data). No melting recipe: a coin is worth more than its metal (§5.2).

4.2 Minting

• Mint press: FE-powered block. Coin blank metal (c:ingots/*) + the right coin die (a tool with durability) → coins. Each strike draws from the server's mint decree (§5.1). The GUI shows today's decree left for your house. Comparator out = decree left.
• Create path: Mechanical Press over a Coin die block on a depot or belt strikes the same coins with rotation instead of FE. Same quota, same ledger. Recipes live in our own recipe type, so no other mod's press (Mekanism, MI, IE metal press) can strike coins.
• Antique coins found in loot are appraised at a bank counter into pennies/groats (drawn from the decree too).

4.3 Carrying and banking

• Coin purse: holds only coins, by denomination, up to a value cap (leather: 640 p, velvet: 6,400 p, gilded: 64,000 p). Picks up coins, makes change, and pays automatically from the Curios belt slot or inventory at every Medici block. Shift-use shows the count; right-click a coin stack to absorb it.
• Strongbox: a protected coin-only block inventory. Owner/team only, blast resistant, can't be broken by others or by machines, no item handler on any side except a configurable owner face.
• Bank counter: opens your account: a coin inventory saved with the world, reachable from any bank counter like an ender chest for coins. At a bank counter you can:
  • exchange: change denominations (free);
  • transfer: move coins from your account to another player's or team's account (1 % fee burned, min 1 p);
  • write a letter of exchange: the coins go into a sealed paper item; the payee (or any bearer, your choice) cashes it at any bank counter. Physical coins inside, so it can be stolen, traded or framed;
  • read your ledger: a double-entry log (debit / credit) of the last 100 movements.
  • appraise antique coins.

4.4 Shops

• Vending machine (two blocks tall, glass front shows the goods): up to 9 offers, each "N × item for P". Buyer pays from purse/inventory, gets change. Stock and till are item handlers: stock goes in from the back/top, coins come out of the bottom, only on faces the owner enables. Works with hoppers, Create funnels, AE2 interfaces, RS, pipes. Comparator out = stock level of offer 1. Out-of-stock offers grey out. Optional buy mode: the shop buys an item from players for coins out of its till (player-run demand).
• Market stall: a cheaper, unpowered single-offer counter for small sellers.
• Price tag (item): put a price on a Create table-cloth shop or any chest-like display; in v1 it's decor only (Create's shops already take coins as their payment item).
• Every sale pays a market duty (2 % rounded down, min 0) that is burned (§5.3).

4.5 Access, rooms and rides

• Coin slot (wall-mounted coin acceptor): insert the price, get a redstone pulse (length configurable 1 second to 10 minutes) or a toggle. Wire it to a door, a piston gate, a Create contraption, a SecurityCraft reinforced door, a lift.
• Turnstile: lets exactly one paying player (or ticket holder) through, then locks. Rides, museums, bathhouses, train platforms.
• Ticket printer (FE): prints tickets on paper: single-use, timed (1 h, 1 day, 7 days) or season pass, bound to the venue (the printer's id) and optionally to a player. Tickets can be sold from a vending machine.
• Ticket gate (reader): validates a venue's tickets, punches single-use ones, outputs redstone, or acts like a turnstile. CC:Tweaked event with the ticket's holder and type.
• Rental chest: a protected chest that opens for the renter for the paid time (owner sets price per day), then locks again. Storage rooms, shared farms, a market stall's back room.
• Protection is not ours: rooms are protected by FTB Chunks claims and SecurityCraft; Medici only decides who may pass right now and outputs redstone. Our customer-facing blocks are interaction-whitelisted for claims.

4.6 Townsfolk and sources

• The Merchant: a wandering trader variant who arrives at the market (a trading house block marks it), posts 3–5 wishes ("32 glass panes for 4 groats"), pays from the decree, and leaves after a day. Prices fall with each delivery. This is how newcomers earn without a mint, and how the server's surplus finds a buyer. He also visits MineColonies taverns if present.
• Banker villager (workstation: bank counter): sells cosmetic and convenience goods for coins (velvet purse, Doge's medal strikes, banners, maps to ruins with antique coins). Never buys coins for emeralds (that would make a villager hall into a mint).

4.7 Found money: mob drops and loot

Money turns up where someone would have carried or hidden it. Two kinds:

• Coins (real money): small amounts from mobs and chests, drawn from the decree's fortune share (§5.1). When the fortune share for the day is spent, mobs drop nothing and chests roll antique coins instead.
• Antique coins (worn ducats, Byzantine hyperpyra, old groats): not money until a bank counter appraises them (that draws from the decree too). They can always drop, so loot never feels empty, and finding a pouch of them is a reason to visit the bank.

Mobs (only on a real player's kill: no fake players, no machines, no spawner- or egg-spawned mobs, per-player daily cap; Looting adds a little):

Never from animals, endermen, skeletons, slimes, creepers or spiders. Wandering traders and villagers drop nothing (killing them must never pay).

Chests (global loot modifiers on vanilla and ATM10 structure tables, Lootr-compatible):

All tables are data (data/medici/loot_modifiers/, data/medici/mob_drops/) and can be turned off or reshaped per pack. Spawn reason is tagged on the entity when it spawns, so the check is cheap.

4.8 Building the city: the Venetian block set

A market square, a bank hall and a canal need a look you can't get from vanilla stone. Medici ships an extensive, builder-first set: 14 families, about 230 blocks. They're decoration only, separate from the mechanics, and they never gate anything, so the "light" rule (§1) still holds for gameplay.

Rules for every family:

• Full shape set where it makes sense: block, slab, stairs, wall; plus vertical slab and the family's special pieces. Slabs, stairs, walls, fences, balustrades and mooring poles are waterloggable: this is a canal city.
• Stonecutter for every stone shape from the base block; plaster and wood variants by dye/crafting.
• Clean base + weathered variant: the base block is always clean (builds stay crisp); worn, peeling, mossy or waterline variants are separate blocks.
• Connected textures where seams would look wrong (Istrian stone ashlar, marble slabs, canal walls, leaded glass), through CTM/Fusion, both in ATM10; plain textures that still tile when neither is loaded.

4.8.1 Families

Glass chandeliers, mirrors, millefiori vases and lace come from the Artist (§4.9). A gondola (a long, two-seat boat with a standing gondolier spot, larch or black lacquer) rounds out the canal.

4.8.2 Plays well with ATM10's builders

4.8.3 Showcase and blueprints

Six showcase builds made only from Medici + vanilla blocks: canal house, bank hall, mint, market square, bridge over a canal, palazzo facade. They ship as structure files (/medici showcase <name>) and as Create schematics so players can print them with a schematicannon. They are also the scenes for the renders and the site (§7).

4.8.4 Starter decor (ships first)

The original small decor set stays as its own list. It ships with v0.1/v1.0 no matter how far the families above have got, because these are the pieces a market square and a bank hall need on day one:

Terrazzo (3 colours), Istrian stone (block, slab, stairs, column), Venetian red plaster, gold-leaf mosaic, coin pile (1–8 layers, decorative, made from coins and returns them), abacus, money scales, ledger desk, bell-tower lantern, striped mooring pole.

When a full family lands (§4.8.1), its starter blocks become part of it with the same ids, so nothing built with the starter set breaks.

4.9 The Arts: the Artist and commissioned art

Rich merchants paid painters to put them in front of Venice; so can players. The Artist is a resident NPC who sets up at a studio easel and takes commissions for coins. Every coin paid is burned, so art is the mod's biggest voluntary sink: the reason to have money once you have everything.

4.9.1 How a commission works

1. Place a studio easel in a roofed room with light (the studio). The Artist arrives at the next dawn and stays while the studio stands (one Artist per studio; config caps studios per house).
2. Talk to him: pick the kind (portrait, statue, city view, ceiling fresco, mask, coat of arms, …), the subject (you, a team mate who is in the studio, or your whole team for a group portrait), the size and the tier. The price is shown before you pay.
3. He paints on the easel (you watch the canvas fill, a few in-game hours to three days by tier) and the work is delivered to the easel's output, wrapped and signed.

Price and chance. The tier is the price, like a Renaissance contract: patrons paid for the size, the number of figures, the pigments (fine ultramarine was as costly as gold leaf and was often billed separately) and for work "by the master's own hand" rather than by the workshop. Venice paid its official painters per Doge portrait:

Quality: fine (normal), masterwork (signed, gilt detail, a subtle shimmer, rare variants such as the night, fog or carnival version of a motif). Masterwork chance: 0 / 2 / 8 / 15 / 100 % by tier; every fifth Grand commission without a masterwork is guaranteed one.

Fair chance, not gambling. You always get the kind, size, subject and frame family you paid for; chance only picks among motifs and the finish, and from the Commission tier up you choose among three sketches. The GUI shows the odds. There are no rerolls ("the Master does not repaint"), no spinning animations, and no NPC buys art back, so there's no coin loop. Better results cost more with certainty (the Masterpiece tier is "by the master's own hand"), not more pulls. Coins are earned in game only. Art is real items: hang it, trade it, sell rare masterworks from a vending machine. That's where the fun market is.

Optional pigments raise the odds a little and are a use for ATM10 surplus: ultramarine (lapis + a Mekanism enrichment or a crusher, any c:dusts/lapis) +5 % masterwork, gold leaf (pressed from gold) unlocks gilt frames at Commission tier.

4.9.2 What he makes

4.9.3 The motif plan (dozens, data-driven)

All motifs are data (data/<ns>/medici/art/motif/*.json + textures), so packs and servers can add their own; ours are drawn in house (ART_SPEC §8).

• Portrait backgrounds (24): the Grand Canal at noon, the Rialto bridge, St Mark's square, the Doge's palace loggia, the lagoon at sunset, carnival night with lanterns, a foggy canal, the bell tower by moonlight, a glass furnace, the shipyard, a coloured fishing village, a villa garden on the river, the library, the map room, a storm at sea, the market, a gondola ride, your bank hall, your mint; and five modern ones painted in the old manner: in front of a Create windmill, an AE2 network wall, a fusion reactor, a rocket on its pad, a mob farm (the Artist "does not ask questions").
• Poses (8): standing, hand on hip, holding a ducat, with ledger and quill, gondolier with oar, masked, pointing at the horizon, seated (bust only: three-quarter view).
• Frames (12): plain pine, walnut, black lacquer, carved gilt, gold-leaf masterwork, oval, round, mirror-glass, carnival ribbons, ship's porthole, copper industrial with rivets, ice-and-silver (for frozen-biome bases).
• City views (24): 1×1 to 4×3 vanilla painting variants: the canal bend, the regatta, the frozen lagoon, the arsenal gate, the fish market, the bridge of the merchants, rooftops and chimneys, island cemetery of cypresses, the lighthouse, a Venetian galley, a sea of masks, the night procession, … plus "the Venice of elsewhere": the Nether canal, the End lagoon (dimension views only appear if that dimension exists).
• Ceiling frescos (12), mosaics (12), masks (6 shapes × 8 patterns), crest charges (12), shop sign icons (16).

Total for v1: about 130 pieces of art. That's a lot of pixels: they come in waves (§8), and the first wave (8 backgrounds, 4 frames, 8 city views, 3 frescos, 3 masks) is enough to ship the Artist.

4.9.4 Rendering, skins and performance

• Skins: the commission stores new ResolvableProfile(serverPlayer.getGameProfile()) at commission time, with the signed texture property (like a player head), so portraits and statues keep the look they were painted with and need no name lookup later (name lookups go wrong on offline-mode servers). Missing texture → a default "anonymous patron" skin.
• Only references travel: the server stores {profile, motif, frame, pose, tier, seed}; no image data is uploaded or synced (the bandwidth and moderation cost of upload-your-own-image mods like Immersive Paintings, which isn't in ATM10 anyway).
• Client-side compose, cached: a portrait's texture (background + skin pose + frame) is composed once on the client into a DynamicTexture, keyed by (skin hash, motif, pose, frame, quality), with an LRU cap (config, default
  64. and released when unused. The server never renders. Statues recolour the skin into the material's ramp on the CPU once per (skin, material) and render the vanilla player model in a block-entity renderer (the same approach as Supplementaries' statue). No custom shaders: they tend to clash with shader packs.
• Collection: a gallery catalogue page in The Merchant's Handbook tracks motifs you've owned; advancements for sets (all canal views, every mask, a masterwork of each kind).

5. Money supply (the one rule)

Details and numbers in ECONOMY.md.

5.1 The decree

Coins enter the world only through the mint decree: a server-wide budget in pennies that refills every day (24 h real time). The mint, the Merchant, mob drops, chest loot, appraisals and quest rewards (if the pack wires them through our API) all draw from it. The refill shrinks as the money supply approaches a target per active player, so the economy can't hyperinflate no matter how much gold an ATM10 base produces. The admin sees it in one line:

/medici decree → Decree: 1,240 p left today · supply 182,400 p / target 240,000 p · 12 active players

5.2 Why metal can't break it

ATM10 can produce gold by the stack per minute (Mekanism ore processing, Mystical Agriculture, AE2/MI automation). If a gold ingot always became 2 ducats, the ducat would be worth nothing. So the metal is the blank, not the value: striking costs metal, power and die wear, and is capped by the decree. A coin is always worth more than its metal, so nobody melts coins (and there's no recipe to do it).

5.3 Sinks

Art commissions (all burned, §4.9; the biggest voluntary sink), market duty on sales (2 %), transfer fee (1 %), Doge's medal strikes, Banker goods, ticket printing paper, die wear, optional pack-dev sinks (claim charters via FTB Chunks bonus claims, waystone tolls) through KubeJS. Burned coins are recorded in the ledger so the supply number stays honest.

6. Integrations (delivery)

All in compat/<modid>/, optional, documented in INTEGRATIONS.md. v1.0 ships: Curios, Jade, JEI (EMI via JEI), Patchouli (The Merchant's Handbook), FTB Chunks tags, FTB Teams ownership, PermissionAPI nodes (FTB Ranks), CC:Tweaked peripherals, Create (coin die press recipe, Ponder scenes), SecurityCraft (redstone into reinforced blocks is vanilla; owner sync is the integration), KubeJS events + recipe schemas, FTB Quests sample chapter (data only). Building set (§4.8.2, data only): Chipped, Rechiseled, Domum Ornamentum, Fusion/CTM; FramedBlocks and Create copycats work by vanilla rules. Spikes: MineColonies (Merchant at taverns, Venetian style pack built from §4.8), Waystones tolls.

7. House standard (from benkl/projectatlantis)

• ModDevGradle 2 + Parchment, runClient/runServer/runData/runGameTestServer, src/generated from datagen only, -PgameDir to run inside the Prism ATM10 instance. JUnit for logic/, GameTests for every block.
• Docs: README, CHANGELOG, CONCEPT, ECONOMY, ROADMAP, RELEASING, DEV_SETUP, MOD_PAGE, LOCALIZATION, CONFIG, INTEGRATIONS, modpack-devs (+ KubeJS examples), compat-report (ATM10), BLOCKS, ADRs, art spec + asset manifest.
• Art: vanilla 16×16, hard pixels, binary alpha, top-left light, hue-shifted ramps, no black outlines, colour budgets; palette = vanilla ramps + Medici accents (Venetian red, lagoon teal, gold leaf, verdigris, velvet, brass).
• Models through the Blockbench MCP, sources in art/blockbench/, checked by tools/art/model-lint.mjs against the Blockbench Minecraft style guide (pixel grid, no sub-pixel, 1 texel = 1 px, ≤ 12 elements, 22.5° rotations, no curves from rotated pieces, 3×3 tiling test).
• Renders and promotion in Blender (Blender MCP for scenes, headless batch for the pipeline): icons, family sheets (one per building family), turntables, the showcase builds (§4.8.3), three hero scenes (the Rialto market at dusk, the mint at work, the carnival ride gate), social cards, press kit, trailer stills.
• Site: Astro static site: home, item catalogue, How the money works, docs, press kit.
• Release: tag v* → GitHub Release from CHANGELOG → Modrinth + CurseForge (ADR 003).

8. Milestones

v0.1 (playable on the server) = M2 + coin purse + vending machine + coin slot + starter decor (§4.8.4).

9. Research notes (2026-11-04)

• ATM10 8.4 (2026-10-29, NeoForge 21.1.265) ships no economy mod: no Lightman's Currency, no Numismatics, no Open Parties and Claims, no EMI, no Accessories. It ships Create 6.0.10 (table-cloth shops take any item as the price tag), FTB Chunks/Teams/Quests/Ranks, SecurityCraft 1.10.2.1, CC:Tweaked + Advanced Peripherals, Curios, KubeJS, Patchouli/Modonomicon/GuideME, Lootr. Source: config/crash_assistant/modlist.json in AllTheMods/ATM-10 and the local instance.
• Gold and silver are effectively free in ATM10 (Mekanism 5×, Industrial Foregoing laser drill, Mystical Agriculture, Productive Bees, piglin farms), so coin value can't come from metal (§5.2).
• What players dislike in existing economy mods: dupes, overflow, permission bypasses, no coin source by default (Numismatics), admins having to strip coin sources out of the config (Lightman's) and asking for sinks.
• History: ducat 1284 (3.5 grams of gold, 124 pennies by 1472), groat 1193, lira = 20 pennies; Banco della Piazza di Rialto 1587, Banco del Giro 1619; Pacioli's Summa printed in Venice 1494; Fondaco dei Tedeschi. We use decimal ratios (§4.1) for playability; the guidebook tells the real ones.

10. Risks