Minecraft /execute if PREDICATE [1.19] Command Tutorial

What is a predicate? A predicate  is a part of a datapack.  In the base game, they are used for loot tables  E.G, when mobs should drop certain kinds of loot,   what type of loot to generate in chests, etc. A predicate tells us whether something is true  

Or false. The “Something” it tells us is  called a condition, and there’s a looong list   of condititions that are built into Minecraft.  There’s conditions for just about everything,   from detecting your position in the  world, checking scoreboard values,  

And even checking light levels! The full list of  them is on the Minecraft wiki page for predicates.  Predicates are often used as an alternative to  having tons of scoreboards. However, there are   some things that can only be done with predicates! So, when should you use a predicate? 

1. When you need to detect a  large number of criterias at once.  2. When you are trying to reduce  the number of scoreboards in use.  3. When something can only  be detected by a predicate.  Let’s have a look at making one now. Given that  it’s a JSON file, predicates are very easy for  

Computers to read, but fairly annoying  to write as a human. Because of that,   I’m gonna use a generator. This is  a quite popular and up-to-date one.   The link is misode.github.io/predicate/ and  it’s in the description for you to go click on. 

Let’s start with a pretty common use case for  predicates. Detecting if a player is sneaking! Our first condition here is called “entity  properties” and it contains just about everything   you can think of to do with entities. It’s got  entity type, NBT, team- but what we want is  

Under “flags”. Click on the plus to add a “flags”  condition. Then we’ll click on is_sneaking: true.  Now to get our predicate into the game. I’m gonna  assume you’re familiar with how to set up a basic   datapack for this video (just like this one), but  if you’re not, go watch my datapack tutorial after  

This video. While I’m shamelessly cross-promoting  myself, subscribe if you want to see more   quality command/datapack videos like this one! Anyway, open up your datapack folder and go into   data, then create a namespace for your project if  you haven’t already. Mine is called “tutorial”.  

Brilliant. Inside that (this is where the new  stuff happens) create a folder called “predicates”   spelled just like that. Inside here is where  we will put the predicates. You can either copy   and paste the predicate into a new json file  (called something like “is_sneaking.json”),  

Or you can download your predicate as a json file,  then move and rename it once it’s downloaded.  Now we can go in game and do /reload. Our  predicates are now loaded! There’s a number   of different ways to use predicates in commands,  and no one is truly superior to any other, so let  

Me show you some options. First, there’s what  you came here to see: /execute if predicate.   I’ll write the command /execute as @a if predicate  tutorial:is_sneaking run say I’m sneaking! . What   this does can be broken down into 3 parts. First,  /execute as @a, run the following once for each  

Player. If predicate tutorial:is_sneaking, so *if*  this player is sneaking, then run the say command,   and say “I’m sneaking!” Let’s make this  run every tick and see what we get.  Nothing, until I start holding sneak, then  the chat gets flooded with messages! Nice! 

The second way to do this would be to use the  target selector form of predicate. Meaning   we can use a predicate to only select  certain players! For example: /execute as   @a[predicate=tutorial:is_sneaking]  run say I’m sneaking! This command does exactly the same thing as  our last command, but the predicate is built  

Into the player selector, instead of using  an execute if command. Is this better or   worse than the previous way? Not really, it’s  just different. I use this version less often,   just because I don’t like how crowded it gets, and  more importantly because Minecraft doesn’t let you  

Tab-complete your predicates this way. Get on it  Mojang! Alll the cool kids let you tab complete   in your player-selectors! (2nd example)  Our 2nd example is using a random-chance condition  to make something happen a certain percent of the   time. Just choose random chance as our condition,  and write a percentage as a decimal between  

0 and 1. I’ll choose 0.5, giving this predicate a  50% chance of being true every time it’s checked.  I’ve added the predicate to my folder and  reloaded. If you forgot how to do that already   then too bad the information is gone forev- wait  actually I’ve just been informed this is not a  

Live broadcast on television, and you go back and  look again. Ok good good. Now, we could check our   50% chance on just ourselves, but that’s boring.  Instead I’ve recruited my friend logbog, digdog,   bigbog or zigzog, eggnog, leap frog, hotdog,  wigwog, tall man, colonel sand, homestuck fan,  

Haunted lands, big band, grand cayn, loves  mans, I’ll be damned- to help with the commands.  These are fake players created by the carpet mod  by the way. They behave just like real players   for testing purposes, but aren’t controlled  by humans because this is still singleplayer.  

This is my command, don’t mind how long  it is, basically all it does is: execute   as @a[predicate=tutorial:50_percent] and also  whose name is not my username. If that 50% chance   condition is met, then it runs a particle command. *press* Each time I run this command,  

Every player basically does a coin flip. If they  win the flip, then the particles go off. It won’t   choose exactly 50% of people every time, but each  player has a 50% chance of running the command. Our 3rd example is detecting players below a  certain Y-level. I’ve gotten several comments  

Asking how to do this, usually for a bedwars  inspired map. For this we’ll need a “location”   flag which can be found under “entity  properties”. Click the plus, then go down   and click the plus next to “position”. Then in  the Y section we want to change it from number  

To object, which will let us pick a range of  numbers, instead of just looking for one specific   number. The first number here is the minimum  height we’re looking for and the second is the   maximum. I’ll set these to 0 and 60 respectively. After adding it to my predicates folder,  

Naming it something appropriate  like “is_y_less_than_60.json”   and reloading in the game, we can test it  with a command. Here’s my example command!  /execute as @a (pretty basic) if  predicate tutorial:is_y_less_than_60   run- a command that just says “My y <=  60!” Awesome, and we switch this on.  Ground level in this world is 64, so if we go  more than 4 blocks down this should activate!   Keep an eye on my Y coordinate in the top left. One, two, three, four- and there it is! Any lower   Than this and it’ll just keep spamming.  But as soon as we go back to the surface   it’ll fade away. No more new  messages are getting sent. Something else we can do with the “location”  condition is detect light levels! Add a “light”   Condition and set it to object. Now we can  enter the min and max light we want to detect.   I’ll detect 0 through 7, as that’s what  Minecraft considers “dark” for mob spawning.  Bim bam boom added to the game,  reload, and here’s our command:  /execute as @a if predicate  tutorial:is_dark run say I’m in the dark!  Just like the last one! Now if  we go into my spooky dungeon,   we should know when we’re in the dark.  Oooooooo, scary. And also very cool! There are many other cool things you can  detect with predicates such as time of day,   Biome, and even scoreboard values. I’ll  leave figuring those out to you as homework.   If you want to know what any of the other  conditions do, the first place to look   is this wiki page (link in the description).  It’s got a nice list of all the conditions and   What they do in pretty good detail most  of the time! If you have more questions   or suggestions feel free to leave them  in the comments. Also subscribe so you   can get more videos like this one! I’ve  been Legitimoose, thank you for watching.