p.boxed.
  Win by playing a move on the middle of last rank.
  The king has no royal status.

p.
  The goal for White (resp. Black) are the squares d8 and e8 (resp. d1 and
  e1) in the middle of the opposing rank. The first player to settle a
  piece there wins, even if it is attacked.

figure.diagram-container
  .diagram
    | fen:2r5/p1p1b2p/1pbp4/5K2/P1PP4/1P6/4nPPP/3R1NR1 c3:
  figcaption 1...Nc3 and 2...N(x)d1# wins for Black.

h3 Source

p
  | This variant is mentioned 
  a(href="http://abrobecker.free.fr/chess/fairyblitz.htm#football")
    | on this page
  | . It isn't specified if the winning piece needs to be safe from attacks.