A gamerule is a command that a player can run to change how the game is played. So in general a gamerule command can change allot of things. As of the latest update to the game 1.7.5 there are 11 gamerule commands. To run any of these commands just copy them from the page and put them in the chat window. Then hit enter, it’s as simple as that. When you run these gamerule commands they are not permanent but, will stay in motion till you change them with a changing gamerule command.

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/gamerule commandBlockOutput


Command Block Output is a command for command blocks. This command will tell the game whether or not the game will tell a player if a command has been run in a command block and if it was successful or not. Now if you are running lots of commands though command blocks this will cause your chat to fill up with tons of code. So if you want to get rid of the command block output in chat, just run this command.

/gamerule commandBlockOutput false

But if some reason you want to see the command block output run this command

/gamerule commandBlockOutput true


Finally if you are using tellraw or the say command; They will still show up in chat when the gamerule is set to false. 

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/gamerule doDaylightCycle


Now the doDaylightCycle command controls how the sun and the moon work. When this command is set to true the day night cycle will act as normal does. But when set to false this command will tell the game to stop time from moving. So if you run this command during a Minecraft day it will say day forever and vise versa if you run this command in the night it will say night forever. Side note you can still use the /time set command with this command set to false.


/gamerule doDaylightCycle true

/gamerule doDaylightCycle false

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/gamerule doFireTick


This game rule controls how fire and lava act. When this command is set to true fire and lava will act as it always does, spreading and causing general chaos. But when this command is set to false, fire will not spread or go out. So you can use fire anywhere without the fear of it spreading and destroying a build. Little side note lava will still set stuff on fire but the fire will not consume anything.  Also fire and lava will still set the player and other mobs on fire no matter what the state of the command is.

/gamerule doFireTick true

/gamerule doFireTick false
 

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/gamerule doMobLoot

Mob loot is an interesting command, when you kill any mob and this command is set to true you will get your normal drops from the dead mob. However, if the doMobLoot command is set to false, the killed mobs will not drop anything. Now this command only applies to  loot not experience that the mob drops.  

/gamerule doMobLoot true

/gamerule doMobLoot false

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/gamerule doMobSpawning


Now mob spawning is one of the most powerful commands. It tells the game if mobs should spawn and this applies to all mobs. That includes all natural spawning peaceful and hostile mobs. Now the player can still spawn in mobs with spawn eggs, commands, or monster spawners. Now when this command only applies to mobs that haven’t been spawned in yet by the game.  All mobs in the game at the moment the command activated will not be affected by this command. So when this command is set to true mobs will spawn normally. When the command is set to false mobs will not spawn.

/gamerule doMobSpawning true

/gamerule doMobSpawning false

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/gamerule doTileDrops


First of all a Tile is a block, so when you set this command to false, the game will not produce any items when you break a block. In addition, this includes any tile broken even if the player didn’t break it. This feature can be useful for the elimination of lag, keeping creative building inventories clean of pointless items, and if you are making a mini game and you don’t want the players of the game from cheating. Therefore, when this command is set to true the game will act normal with tile drops. Then when the command is set to false there will be no tile drops.

/gamerule doTileDrops true

/gamerule doTileDrops false

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/gamerule keepInventory


This gamerule applies to the players inventory. When this command is set to False, the player will lose their inventory as normal. However, when this command is set to True the player will keep their inventory when they die. This also is true for the experience the player has.

/gamerule keepInventory true

/gamerule keepInventory false

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/gamerule logAdminCommands


This game rule mostly applies to sever. When you are running a server, it will keep a log of all actions that happen in the game. Like deaths, players joining and leving the game, and command block read outs. However, if you are running allot of commands from command blocks it will fill this log up really fast. So to combat this you set this command to false and it will stop command blocks from spamming this log.


/gamerule logAdminCommands true

/gamerule logAdminCommands false

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/gamerule mobGriefing


Mob griefing can be very frustrating and annoying when playing the game. This command can stop all mob griefing; Enderman will not be steeling any more blocks, Creepers will not be destroying any blocks when they blowup, Zombies will stop breaking doors, Ghast’s fire balls will not destroy the terrain, and the Ender Dragon will not be able to destroy everything it touches.  When the command is set to false all mob griefing will stop.


/gamerule mobGriefing true

/gamerule mobGriefing false

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/gamerule naturalRegeneration


Natural regeneration is the regeneration of health, when in survival mode or adventure mode. So when this command is set to false a player can only regenerate health from beacons, golden apples, and potions. A full hunger bar will not regenerate more health. This game rule is used in all the UHC matches to increase the intensity of the game. Therefore, when the game rule is set to true a player can regenerate health with a full hunger bar. If it’s set to false the player cannot regenerate health from their hunger bar.

/gamerule naturalRegeneration true


/gamerule naturalRegeneration false

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/gamerule randomTickSpeed

random tick speed is how fast the game lets plaints grow and leaves decay. With most plaints in minecraft there are different grow stages. For a plaint to grow it must receive a tick update from the game. 
These are generated randomly throughout the game. This gamerule can edit how often these events happen. The game is normally set to 3 but you can increase or decrees this as much as you want. If you have 
a custom map you may want to set this to 0. So there will be less lag and non of you plaints will change. But if you have a survival world and you want to decrees the amount of time you spent waiting on plaints
to grow, increase this gamerule. Be warned that if you raise this number to much you can lag out your world. If you want you plaints to grow faster keep the number 20 and you should be fine. You can set this gamerule to True and False but I'm not really sure what that does.

/gamerule randomTickSpeed 0

/gamerule randomTickSpeed 20
 

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/gamerule showDeathMessages


Now death messages are when the game tells you when a player dies in chat. Weather that be in single player or multi-player it works either way. If the gamerule is set to false the game will not tell you when a player dies, but when set to true the game will. Also this gamerule is set to true when you start a new world


/gamerule showDeathMessages true

/gamerule showDeathMessages false

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Personal Preference of GameRules
Now when I set up a new world for a build project I like setting these gamerules. Therefore, the game will be more enjoyable to play.


/gamerule commandBlockOutput false


/gamerule doDaylightCycle false


/gamerule doFireTick false


/gamerule doMobLoot false


/gamerule doMobSpawning false


/gamerule doTileDrops false


/gamerule keepInventory true


/gamerule logAdminCommands false


/gamerule mobGriefing false


/gamerule randomTickSpeed 0


/gamerule showDeathMessages false