Merchant Discount Potion

Summary

Stackable splash potions that temporarily reduce villager and wandering-trader prices while preserving vanilla trading rules.

Description

Merchant Discount Potion adds two brewing-stand-created splash potions for Minecraft Java 1.19.4 and 1.20.1 with Forge. Throw them near adult villagers or wandering traders to temporarily reduce the first payment stack of their trades.

Features

• Merchant Discount I adds 12.5 percentage points and 8 minutes.
• Merchant Discount II adds 25 percentage points and 12 minutes.
• I deals 1 damage and II deals 2 damage to each adult merchant hit. The damage can kill but is unattributed: it does not create villager reputation penalties, golem anger or trader-llama retaliation. Vanilla hurt invulnerability is retained, so a bottle that cannot damage a protected target also cannot add discount.
• Discount strength stacks up to 100%; duration accumulates with every successful hit, including at maximum strength.
• Every merchant inside the vanilla splash radius receives the full added duration, without distance falloff.
• Works with adult villagers and wandering traders; baby villagers and other entities are unaffected.
• All players share the affected merchant's temporary effect, while each player's vanilla reputation, curing and Hero of the Village modifiers remain individually calculated below 100%.
• Only the first payment stack is reduced. The second payment and merchant output never increase or change.
• Open trade screens update immediately when the effect is upgraded or expires.
• Absolute game-time expiration survives chunk unloading and normal server restarts. Server downtime does not consume duration.
• Custom brewing recipes, dispenser support, English and Simplified Chinese translations.
• No configuration file, commands, telemetry, network service or required library mod.

Brewing

• Splash Awkward Potion + Emerald → Splash Potion of Merchant Discount I
• Merchant Discount I + Glowstone Dust → Merchant Discount II

One ingredient processes up to three bottles. Redstone, Gunpowder and Dragon's Breath cannot convert these custom potions into other forms.

Price calculation

Below 100%, the mod subtracts at least one item and otherwise floor(base first-payment count × accumulated rate) from the vanilla-calculated current price. The result never falls below one. At 100%, the first payment is forced to one. Demand, reputation, curing and Hero of the Village remain part of the vanilla baseline below full strength.

Requirements

• Minecraft Java Edition 1.19.4 or 1.20.1, using the matching JAR
• Forge 45.3.8–45.4.x for 1.19.4, or Forge 47.4.10–47.x for 1.20.1
• Java 17
• Required on both the server and every connecting client

Version 1.2.0 is offered as Beta. Both target builds passed automated compilation, 8,217 numerical assertions, 32,768 boundary checks and all 10 required Forge GameTests. Earlier 1.19.4 builds also passed graphical-client transaction, chunk-unload and normal-restart checks, but those older checks do not replace a full manual regression of both 1.2.0 files. Human external dedicated-server multiplayer and long-term compatibility testing remain limited; back up important worlds before adding or removing mods.

AI disclosure: this project was developed with substantial generative-AI assistance for code, translations, testing support, page text and the project avatar, under human direction and design decisions. The maintainer reviewed the behavior, selected the balance rules and is responsible for the distributed release. The avatar is AI-generated branding artwork and is not an in-game screenshot. Gallery images are unmodified in-game screenshots.

You may include the unmodified official JAR in free modpacks with credit and a link to this project page. Standalone rehosting, resale and claiming authorship are not permitted. All other rights are reserved.

NOT AN OFFICIAL MINECRAFT PRODUCT. NOT APPROVED BY OR ASSOCIATED WITH MOJANG OR MICROSOFT.

Changelog 1.2.0

• Adds 1 damage to Discount I and 2 damage to Discount II for adult merchant targets.
• Damage is deliberately unattributed, preventing vanilla reputation and retaliation side effects.
• Retains vanilla hurt invulnerability; a bottle that cannot deal its health cost cannot add a free discount.
• Excludes baby villagers from both damage and discount.
• Adds a Forge 45.3.8-compatible Minecraft 1.19.4 build and a separate Minecraft 1.20.1 Forge build.

Changelog 1.1.0

• Initial public beta.
• Adds Merchant Discount I (+12.5%, +8 min) and II (+25%, +12 min).
• Adds cumulative strength up to 100% and cumulative duration.
• Adds villager and wandering-trader live trade synchronization and recovery safeguards.
• Adds brewing, dispenser support, English and Simplified Chinese localization.