Gameplay Commands

Difficulty

Run /difficulty on its own to see the current setting, or add peaceful, easy, normal or hard to change it. Java has wanted the full word since 1.13; the numbers 0 to 3 and single letters only work on Bedrock.

Two things catch server owners out. The change only lasts until the next restart, because the server reads the difficulty from server.properties when it starts, so set it there as well if you mean it. And on a Hardcore world the command reports success while the difficulty stays exactly where it was.

Game rules have new names since 1.21.11

Java 1.21.11 gave every game rule a snake_case name. If a guide tells you to type keepInventory, it was written for an older version. These are the rules people look up most, the way /gamerule expects them now:

keep_inventory

Players keep their items and experience when they die. Off by default. Used to be keepInventory.

advance_time

Day, night and the moon phases keep moving. On by default. Used to be doDaylightCycle.

advance_weather

The weather changes by itself. On by default, and /weather still works when it is off. Used to be doWeatherCycle.

mob_griefing

Creepers, endermen, ravagers, withers and other mobs can change blocks. On by default. Used to be mobGriefing.

random_tick_speed

Random ticks per chunk section per game tick, the thing behind crop growth and leaf decay. Default 3, and 0 switches random ticks off. Used to be randomTickSpeed.

players_sleeping_percentage

The share of players in the Overworld, in percent, who have to sleep to skip the night. Default 100; at 0 a single sleeper is enough. Used to be playersSleepingPercentage.

spawn_phantoms

Phantoms spawn at night. On by default. Used to be doInsomnia.

fire_spread_radius_around_player

How far from a player fire can spread. Default 128 blocks; 0 stops fire spreading and -1 removes the limit. Replaced doFireTick.

Pair advance_time and advance_weather with the time and weather commands when you want a fixed noon or a storm that never ends.

Default game mode

/defaultgamemode sets the mode a player gets on their very first join. It only touches people who are already online when force-gamemode=true in server.properties, or when the world is open to LAN, and then everyone online switches at once. To change specific players, use /gamemode.

All three commands need permission level 2.