How to Host a Mineshafts and Monsters Server

What Is Mineshafts and Monsters?

Mineshafts and Monsters (M&M) is an RPG-focused modpack built on Forge for Minecraft 1.12.2. It transforms Minecraft into a story-driven adventure with custom quests, NPCs, dungeons, boss fights, and a class system. The pack features mods like CustomNPCs, Tough As Nails, Tinkers' Construct, and a custom world with hand-built towns, quest lines, and lore. M&M feels less like a traditional modpack and more like an RPG built inside Minecraft.

Because the pack relies on a pre-built world with custom NPCs and quest data, hosting requires a bit more care than standard packs. If you want to host a Mineshafts and Monsters server, you need to preserve the custom world and NPC data during setup.

Server Requirements

Forge and Java Version

M&M runs on Minecraft 1.12.2 with Forge, requiring Java 8. Do not use Java 17 or 21, Forge for 1.12.2 crashes on modern runtimes due to reflection and class-loading changes. Install openjdk-8-jre-headless on Linux or select Java 8 in your panel's dropdown.

RAM Allocation

Player Count	Minimum RAM	Recommended RAM
1–5 players	4 GB	6 GB
6–12 players	6 GB	8 GB
12–20 players	8 GB	10 GB

M&M is moderate in size at around 150 mods, but CustomNPCs with full dialogue trees and quest scripts can consume unexpected memory. The custom world is also large. Use the RAM calculator and lean toward the recommended values when you host a Mineshafts and Monsters server.

Downloading and Installing

Download the M&M server pack from the official source (Technic Launcher page or the project's website). The server pack includes the custom world, NPC data, and quest files. Extract everything into your server directory, preserving the folder structure exactly.

Start the server:

java -Xms4G -Xmx6G -jar forge-1.12.2-*.jar nogui

Accept the EULA and restart. The first boot loads the custom world, which takes 3 to 5 minutes because the pre-built terrain and NPC data need to initialize.

Config Tweaks

CustomNPCs Settings

The CustomNPCs mod drives the RPG experience. Quest givers, shop vendors, and story NPCs are placed throughout the world. If NPCs vanish after a restart, check that the customnpcs/ folder in your world save is intact. Corrupted NPC data is the most common issue on M&M servers.

Difficulty Scaling

M&M has custom difficulty settings that control mob damage, player health regen, and hunger drain via Tough As Nails. Adjust these in the relevant mod configs if your players find the default settings too punishing or too easy.

Common Issues

Custom World Not Loading

If the server generates a vanilla world instead of the custom M&M world, the world folder was not placed correctly. The level-name in server.properties must match the folder name of the custom world included in the server pack. Double-check the path.

NPC Desync

Players occasionally report NPCs that do not respond or give wrong quest dialogue. This usually happens after a server crash mid-save. Keep regular backups of the customnpcs/ directory and the world save. Restoring from a clean backup resolves most NPC issues.

Performance Tuning

Set view-distance=8 in server.properties. The custom world is dense with structures and NPCs, so shorter view distances reduce the number of entities the server ticks simultaneously.

JVM flags for Java 8:

java -Xms4G -Xmx6G -XX:+UseG1GC -XX:MaxGCPauseMillis=100
-XX:+UnlockExperimentalVMOptions -XX:G1NewSizePercent=30
-XX:G1MaxNewSizePercent=40 -XX:G1HeapRegionSize=8M
-XX:G1ReservePercent=20 -XX:InitiatingHeapOccupancyPercent=15
-jar forge-1.12.2-*.jar nogui

Java 8 G1 tuning differs from modern versions, see our JVM flags guide for details. For another 1.12.2 pack, check our RLCraft hosting guide. If you want something lighter and more modern, the Better MC guide is a good comparison.

Try our server: Astroworld MC, IP play.astroworldmc.com, Java + Bedrock.