Is it possible to make a command with one command block that:
- change the block below a player
- in a given radius from some coordinates
- and if it is possible: for more than 1 players
you already have the command:
/setblock ~0 ~-1 ~0 air (but a player have to type this)
so is it possible to do this for a player?
even a small part will help.
Unfortunately, the /setblock command does not have the capability of easily targeting a player and setting blocks relative to that player. In order to accomplish this, you would need a constrained area and hundreds of command blocks checking specifically where the player is, and running from there. It's basically no different than previous methods, except it uses a different command as the end result.