on damage of a player:
  set {walka.%attacker%} to 20
  set {walka.%victim%} to 20
every 1 second:
  loop all players:
    if {walka.%loop-player%} is bigger than 0:
      set {walka.%loop-player%} to {walka.%loop-player%}-1
    display "&l&bJestes podczas walki" on bossbar with 100 percent by 20 seconds for loop-player
on quit:
  {walka.%player%} is true:
    set {walka.%player%} to false
    kill player
on command:
  {walka.%player%} is true:
    cancel event
    send "&eNie mozesz uzywac komend podczas walki!"