Need help with /spreadplayers command

Question

So, I am making a mini game and I want it to put all of the players in one of the five maps that they have selected. I put bedrock walls about 20 blocks high all around the map, and barriers on the ceiling. However, whenever I do a test run, I am put on the barrier roof above the map. How to I make it so that it will put them under the roof? This is the command I am using, spreadplayers -35 -14 10 11 false @a[team=Game]. Thanks for any answers!

Answer 1

This is by design, unfortunately; spreadplayers will place players on the highest block on the x/z coordinate it picked.

There is a decent workaround I can think of though: right after the game finishing spreading players, teleport all players 3 blocks or so down (with resistance 5 to stop fall damage). So your command set would look something like this:

spreadplayers -35 -14 10 11 false @a[team=Game]
effect @a[team=Game] minecraft:resistance 60 4
tp @a[team=Game] ~ ~-3 ~

This will spread players, give them resistance 5 for 60 seconds, and teleport them below the barrier allowing them to fall below it. There are some edge cases where this will not work though: for example, your players might end up in a lava lake or an ocean, since this set does not check to see that the block below the player is solid, so keep that in mind.

Answer 2

As UnionHawk said, this is how the command works. But you could remove the bedrock ceiling, then spread the players and then add it back in. The only problem might be lag from the lighting updates.