minetest.register_on_joinplayer(function(player)
	player:set_hp(20)
	player:set_attribute("a:hp",100)
end)

minetest.register_on_player_hpchange(function(player, hp_change)

	if hp_change < 0 then
		local gethp = tonumber(player:get_attribute("a:hp"))
		local newhp = gethp + hp_change
		minetest.chat_send_all(newhp)
		player:set_attribute("a:hp",newhp)

		if newhp <= 0 then
			player:set_attribute("a:hp",100)
			return -20
		end
	end

	if hp_change ~= 20 then
		return 0
	else
		return 20
	end

end, true)