Building a Minigame Plugin for Minecraft

By Biraj Rai April 5, 2020

Minigame plugins are a good way to learn Minecraft server development. They touch almost every part of the API including events, commands, configuration, inventory management, and world handling.

Here is how I approach them.

Core architecture

A minigame plugin needs three things:

Arena management: creating, joining, and leaving game instances
Game state machine: waiting, starting, active, ending
Player inventory handling: saving and restoring items

These should be separate so you can change one without breaking the others.

Game states

I use a simple enum for game states:

public enum GameState {
    WAITING,
    STARTING,
    ACTIVE,
    ENDING,
    RESETTING
}

Each state has different behavior. During WAITING, players can join and leave. During ACTIVE, the game runs. During ENDING, scores are calculated and rewards given.

A tick method controls the flow:

public void tick() {
    switch (state) {
        case WAITING -> handleWaiting();
        case STARTING -> handleStarting();
        case ACTIVE -> handleActive();
        case ENDING -> handleEnding();
    }
}

Configuration

Hardcoding arena data makes the plugin hard to maintain. YAML configuration is better:

arenas:
  lotus:
    display-name: "&bLotus Arena"
    min-players: 2
    max-players: 8
    spawns:
      - world: "world"
        x: 100.5
        y: 64.0
        z: -200.5

This lets server admins add new arenas without touching code.

Inventory handling

The hardest part is saving and restoring player inventories. When a player joins a game, save their inventory. When they die or leave, give it back. Losing a player’s items once is enough to get bad reviews.

public void saveInventory(Player player) {
    savedInventories.put(player.getUniqueId(), player.getInventory().getContents());
    player.getInventory().clear();
}

public void restoreInventory(Player player) {
    ItemStack[] contents = savedInventories.remove(player.getUniqueId());
    if (contents != null) {
        player.getInventory().setContents(contents);
    }
}

Test this code a lot before deploying.

Start small

Do not try to build a full minigame network on your first try. Start with one arena and one game mode. Get it working. Test it with real players. Then expand.

If you are new to Minecraft plugin development, this guide covers the basics.