no plan survives contact with the enemy

• no battle plan survives contact with the enemy
• no battle plan survives first contact with the enemy
• no plan survives first contact with the enemy

• Audio (General Australian):

  (file)

no plan survives contact with the enemy

1. (idiomatic) After a plan against an enemy is drafted, there will be unexpected elements from the opposition that will call for improvisation.
2. (loosely) Even with a preexisting plan, unexpected circumstances will require one to think on one's feet.
   • 2015, Jeph Jacques, Questionable Content (webcomic), Number 2933: Game Over Man, Game Over:

     ‹"No plan survives first contact with the enemy." Or with a pretty girl in a sundress.›