Minecraft Java Edition – How to Create and Use Custom Gamerules?

minecraft-commandsminecraft-java-edition

Recently, there were a few posts about creating custom gamerules, but no question or answer covered the creation and usage of custom gamerules. This post tries to uncover this, but it's just a link-only answer to a tutorial I didn't understand.

From version 1.9 (or maybe earlier), you can create custom gamerules, eg.

/gamerule customGamerule false

This will create a gamerule named customGamerule, currently set to false. It can be changed to true and Bach, but without effect. How can one add an effect to a custom gamerule?

Best Answer

In order to detect the value of any gamerule (both default and custom), CommandStats must be used, which will set the value of the gamerule as a score. Only the QueryResult trigger will be provided with a return value when running /gamerule <name>.

Prerequisites

Objective to hold the value.

/scoreboard objectives add Gamerules dummy

The target of CommandStats must be tracked in the objective in order to obtain the return value. In this case, a fake player named "$customGamerule" will be used to hold the value.

/scoreboard players set $customGamerule Gamerules 0

You can set the custom gamerule's value to any numerical value for detection. If you set it to "true" or "false", it will be interpreted as 1 and 0 respectively. If you set it to any other string, it will be 0.

/gamerule customGamerule 0
/gamerule customGamerule 1
/gamerule customGamerule 100
/gamerule customGamerule true

Detection

Stand on top of the command block and run the following yourself.
```
/stats block ~ ~-1 ~ set QueryResult $customGamerule Gamerules
```
Now every time the command block executes a command that provides a QueryResult return value, fake player "$customGamerule" will have their "Gamerules" score set equal to that value.

The command that will be placed within that command block, which queries the value of the gamerule:
```
/gamerule customGamerule
```
In order to detect the fake player's value, /scoreboard players test must be used.
```
/scoreboard players test $customGamerule Gamerules 1 1
```
Conditional. Command to run if the "customGamerule" gamerule is set to 1.
```
/say "customGamerule" is set to 1.
```

As long as the gamerule is set to "1" or "true", the /say command will execute.

Related Solutions

Minecraft – How to create a villager with custom trade offers

Unless you're running Bukkit with the VillagerShops plugin, there is no way to use command blocks to convert a villager into a chest and vice versa due to the complexity and number of variables... Unless you want a kajillion command blocks.
And trust me, it won't be able to support custom items due to the technical limitations of Minecraft.

The only method sadly, is by using the /summon command.

As you know, summoning custom entities involves the usage of custom NBT tags to custom-define a mob or entity, and villages are no different:

Step 1: Start with a basic villager...

/summon Villager ~ ~ ~

Step 2: Add in the basic information of the villager...
When I say 'basic' information, I meant the profession (look), the career (random trade pool) and any other information.

/summon Villager ~ ~ ~ {Profession: 0, CustomName: "Villager Number 1", CustomNameVisible: 1, Career: 1, CareerLevel: 42, CanPickUpLoot: 0, PersistenceRequired: 1, Invulnerable: 1}

Let's take a closer look at what this means:
Profession: 0 is the profession of the villager. This will determine what he'll look like.

0 - Default Brown Robes
1 - Pink Robes
2 - White Robes
3 - Pink Robes
4 - Black Apron
5 - White Apron
6 - Green Robes

CustomName: "Villager Number 1" is the name of the villager. You can leave this NBT tag out or add a value to it. This name will appear above the villager.
Just remember to keep the quotes as you're defining a string.

CustomNameVisible: 1 is the visibility of the custom name. It can either be 1 or 0.
*If you do not have a CustomName NBT tag, please leave this tag out.

0 - Villager's Custom name will only appear when the cursor is pointing on him.
1 - Villager's custom name will be visible at all times, like players.

Career: 1 is the villager's career. It is essentially the trade offer pool that new offers will be generated out of, which depends on the career number and the profession number.

CareerLevel: 42 is the villager's career level. As of current - It does nothing, but it is essentially the number of times that it has generated new trades.

CanPickupLoot: 0 is a global modifier on all mobs. It can either be 1 or 0.

0 - Villager cannot pick-up anything other than wheat/seeds/whatever while farming.
1 - Villager can pick-up anything, like zombies and players..

PersistanceRequired: 1 is the entity's persistence, it can be used on all entities. It can be set to 1 or 0.

0 - Villager will despawn when the player unloads the chunks it is in.
1 - Villager will never despawn until killed. (Naming the villager achieves the same effect).

Invulnerable: 1 is a self-explanatory tag. It does what it says on the tin and can be used on any entity.

0 - Villager can die, be attacked or be damaged.
1 - Villager cannot die unless /kill is used.

Step 3: Add in the trade information of the villager...
This step is really easy, if you don't get your compound tags mixed up.

/summon Villager ~ ~ ~ {Profession: 0, CustomName: "Villager Number 1", CustomNameVisible: 1, Career: 1, CareerLevel: 42, CanPickUpLoot: 0, PersistenceRequired: 1, Invulnerable: 1, Offers: {Recipes: [{<Trade offer 1>},{<Trade offer 2>},{<Trade Offer 3>}, etc.]}}

Note: The above command is incorrect. You'll need to fill the gaps, remove compounds or add them as needed. It is only an example to illustrate our work-in-progress command.

Our shop is going to be (obviously) simply a series of offers for one item, in exchange for another. Simple enough. Our offer (the replacement of the ` above), should look something like this:

... {buy:{<Item Info>}, buyB:{<Item Info>}, maxUses: 9999999, sell:{<Item Info>}, rewardExp: 10}, ...

... {buy:{id: "Cobblestone", Count: 1}, buyB:{id: "Stone", Count: 2}, maxUses: 9999999, sell:{id: "Cobblestone", Count: 32}, rewardExp: 10}, ...

buy, buyB and sell are the slots where the items are going to go.
Basically, buy and buyB are the inputs while sell is the resulting product.

Inside these values are a compound tag, which is where you can put your item data. Count and id are self-explanatory to the avid Redstoner; Count is the number of items you receive while id is the item name, without the minecraft: bit.

For more information about defining items in the NBT format, look at this wiki page

rewardExp is the amount of experience you'll be given for each successful trade. It can either be a value or false.

<Any number> - This amount of EXP will be given to the player on a successful trade.
false - No EXP will be given to the player.

maxUses is the number of times this trade can be used until the villager needs to be refreshed.

/summon Villager ~1 ~ ~ {Profession: 0, CustomName: "Villager Number 1", CustomNameVisible: 1, Career: 1, CareerLevel: 42, CanPickUpLoot: 0, PersistenceRequired: 1, Invulnerable: 1, Offers: {Recipes: [{buy: { id: "cobblestone", Count: 1}, buyB: {id: "stone", Count: 2}, maxUses: 9999999, sell: {id: "cobblestone", Count: 32}, rewardExp: false}, {buy: {id: "stone", Count: 1, Damage: 1}, buyB: {id: "stone", Count: 2, Damage: 2}, maxUses: 9999999, sell: {id: "stone", Count: 32, Damage: 1}, rewardExp: 10}]}}

Minecraft 1.10 – Custom GameRules Explained

Custom Gamerules makes you add other rules. This is an example:

Enable/Disable every zombie being a baby

/gamerule onlyBabyZombies 1/0

http://www.minecraftforum.net/forums/minecraft-discussion/redstone-discussion-and/redstone-creations/2352873-buffed-mobs-45-gamerule-options

That is one of the custom gamerules. Tutorial on how to make a custom gamerule: http://www.minecraftforum.net/forums/minecraft-discussion/redstone-discussion-and/2353772-tutorial-make-your-own-custom-gamerules