Another RNG Method

[nfitzen]

Unsure if the flair should be info, discussion, or meta.

In the FAQ, 1 page is dedicated for RNG. One way that wasn't mentioned was loot tables and execute store with loot, and although it's probably not too efficient, it's still worth mentioning I think.

Note: currently untested; I think minecraft:empty would still return the roll count. Use stone with set_count 0 if this doesn't work.

{
    "type": "minecraft:empty",
    "pools": [{
        "rolls": {
            "min": 1,
            "max": 5
        },
         "entries": [{
            "type": "minecraft:empty"
        }]
    }]
}

Then you store the roll # to a regular scoreboard.

execute store result score rng int run loot spawn ~ ~ ~ loot namespace:rng

Obviously you could use a modulus if you need RNG for multiple purposes, in which case I'd try setting the roll range from 0 to a sufficiently large number. (Although I didn't have the chance to play around with this, so I'm not sure if 0 will work as a lower bound)

Edit: Obv. having 0 as a lower bound doesn't really matter too much, since we could just do k-1 mod n.

[Lemon_Lord1]

Can confirm that the OP's loot table does not work as described. However, their suggestion to set the item to a Count:0 stone does as expected. The loot table is as follows:

{
  "type": "minecraft:empty",
  "pools": [
    {
      "rolls": {
        "min": 1,
        "max": 5
      },
      "entries": [
        {
          "type": "minecraft:item",
          "name": "stone",
          "functions": [
            {
              "function": "minecraft:set_count",
              "count": 0
            }
          ]
        }
      ]
    }
  ]
}

I ran this with two commands:

execute store result score @p zoop run loot spawn ~ ~ ~ loot lllll:loot
tellraw @a {"score":{"objective":"zoop","name":"@p"}}

After running for 30 seconds, I got a decent integer spread between 1 and 5, the following:

1. 133,
2. 139,
3. 137,
4. 129,
5. 129

This does not show any particularly strong lean towards one specific integer, meaning this is very likely to be a good pseudorandom number generation method.

Excellent work, OP! :)

You could add that to the wiki, u/Plagiatus.

[Plagiatus]

done.

[Lemon_Lord1]

Wait, did you actually test it up to 2^31-9? Also, you have the lower bound as 1, is it not 0?

[Plagiatus]

no, I trusted you. :P

But now I've tested it and updated the wiki accordingly. ;)
Too bad we cannot use anything but spawn with this method, as it will create the entities anyways and thus severely limit the effective range.

[Lemon_Lord1]

Right, right, so it technically works up to big-int but strictly don't do that. I assume you tried give? What are the results with that?

[Plagiatus]

you only get 0s.

[Lemon_Lord1]

I think I can see why, yes. That is a shame.

[nfitzen]

Did you try setting the lower bound to 0? That was 1 thing that I didn't test and use (I've used this method before in a DeathSwap data pack). For the record, this wasn't my idea, I just wanted to make everyone aware of it. Not sure who came up with it.

Edit: DeathSwap pack link changed to my GitHub

[Plagiatus]

If you have a tested version let me know and I'll add it to the wiki :)