bedrock - don't let players go below y=0

init.lua

local bedrock_timer = 0
minetest.register_globalstep(function(dtime)
	bedrock_timer = bedrock_timer + dtime
	for k,player in ipairs(minetest.get_connected_players()) do
		if bedrock_timer < 1 then return end
		bedrock_timer = 0
		local pos = player:getpos()
		if pos.y < -1 then
			player:setpos({x=pos.x,y=2,z=pos.z})
		end
	end
end)