Plumbing Core: Plumbing Minigames for RPG Maker MZ

Plumbing, made playable. Plumbing Core adds a Workshop to your RPG Maker MZ game with six plumbing minigames, a Field Manual that players unlock as they earn stars, and quizzes and exams you can put anywhere in your story. Every round ends with a short “why” that works the answer through with that round’s own numbers, so players learn from every mistake.

Part of the MZ Minigame Collection. This plugin is one of a growing library of themed minigames for RPG Maker MZ, from board games and puzzles to sports, casino and crafting. Mix and match to fill your world with things to do.

👉 See them all: https://itch.io/c/8090415/mz-minigame-collection

It’s one plugin file. There’s nothing to import: every pipe, trap, drain and water heater is drawn by the plugin itself. Units are US customary (psi, feet, inches, gallons, BTU), and code numbers come from the International Plumbing Code.

Three learner levels in one plugin

• Junior (ages 8 and up): ideas and pictures. Why do drains slope? What stops the sewer smell?
• Technician: real rules with clean numbers, like 0.433 psi per foot, ¼ in of fall per foot and fixture units.
• Journeyman: friction and meter losses, IPC slope and trap-arm tables, water closet branch rules and first-hour ratings.

Players pick their level on the first visit and can switch any time. You can also set it from an event, or lock it. Stars and best scores are kept for each level.

The minigames

Minigame	How you play	What it teaches
Pipe Fitter	Rotate the fittings until water reaches every fixture	Elbows, tees, couplings; at Journeyman, no open outlets
Pressure Drop	Read the gauges up a building	psi, 0.433 psi per foot, friction loss, PRVs
Drain Slope	Slide the fall, then flush	¼ in per foot, IPC slope table, fitting it under the floor
Trap & Vent	Spot the drain that keeps its trap seal	Traps, vents, S-traps, trap-arm length
Fixture Units	Total the fixtures and size the branch	Drainage fixture units and the water closet rules
Water Heater	Pick a heater, then watch the morning rush	BTU, recovery rate, first-hour rating, T&P safety

Each game has an intro card, a timer with a speed bonus, a pause menu and a results screen with 0 to 3 stars. Puzzles, including the pipe layouts, are generated fresh every round.

Field Manual, quizzes and exams

• Field Manual: 18 illustrated entries, three per minigame, each written for all three levels. They unlock as players earn stars.
• Pop Quiz: a plugin command with a topic, a number of questions, a pass mark and a pass switch. “Answer three questions about drains and you can start on the job.”
• Certification Exam: one per level, covering all six topics. Passing it awards a certificate made out to the party leader, and turns on a switch you choose.
• Your own questions: add them in the Plugin Manager, with an explanation for each.

Built to drop into your project

• No assets needed. Everything is drawn in code, and the sounds come from your database’s system sounds. Pick your own BGM if you like.
• Results go where you need them. Win switch, score and star variables, a level variable, a total-stars variable and certificate switches.
• Event-friendly. The event waits while a minigame or quiz is open, so you can branch on the result in the very next command.
• Keyboard, gamepad, mouse and touch everywhere. The layout scales to your game’s resolution.
• Runs alongside Engineering Core and HVAC Core. Separate names and save data, so all three can live in one game.
• Saves with the game. One file, no dependencies, and no core scripts edited.

Setup

1. Put EDU_PlumbingCore.js in your project’s js/plugins/ folder.
2. Turn it on in the Plugin Manager.
3. Add the plugin command Open Workshop to an event.

Plugin commands

Open Workshop · Play Minigame · Open Field Manual · Pop Quiz · Take Exam · Set Level · Ask Level · Get Level · Unlock Minigame · Lock Minigame · Unlock Manual Entry · Get Stars · Reset Progress

Script calls

PlumbingCore.tier()                // current level, 0-2
PlumbingCore.stars("slope", 1)     // Drain Slope stars at Technician
PlumbingCore.hasCert(2)            // Journeyman certificate earned?
PlumbingCore.lastResult.win        // last minigame won?

You can also add your own minigames: write one scene class and register it, and it appears in the Workshop. The plugin’s help has a full example.

A note on the content

Code values (slopes, trap seals, trap arms, fixture units, branch sizes, the 80 psi limit) come from the International Plumbing Code, and the game says so wherever it uses them. Codes differ by region and edition, so the Field Manual reminds players to check the code their area has adopted.

Requirements

RPG Maker MZ. Tested against the MZ 1.7.0 core scripts. It does not work in RPG Maker MV.

Terms of use

Free to use in commercial and non-commercial RPG Maker MZ games. Credit is appreciated. Please don’t resell or redistribute the plugin file by itself.

Version history

1.0.0: First release.