Longest Possible Game of War (Card Game): Theoretically Infinite

No official record exists—War has no governing body, no timed tournaments, and games can theoretically never end.

Why It Can Last Forever

• Cycles are possible: Card sequences can repeat exactly, creating infinite loops.
• State space is finite but huge: 52! ≈ 8×10⁶⁷ deck orders; cycle detection is non-trivial.
• No progress guarantee: Unlike games with irreversible state changes (captured pieces, score), War only permutes cards.

Mathematical Results

• Expected length (2 players, 52 cards): ~200–300 turns (simulations).
• Maximum finite length: Unknown; lower bounds in thousands of turns.
• Infinite games exist: Proven for certain initial arrangements (e.g., symmetric deals).

What Makes Games Long

• Even card distribution (both players get balanced high/low cards).
• Frequent wars (ties) that redistribute cards without resolution.
• 3+ players: exponential state explosion; practically never finishes.

Practical Answer

Longest recorded casual game: anecdotes of 2–4 hours. Longest theoretical game: infinite. If you're playing War and it passes 30 minutes—shuffle and start over. Or switch to Gin Rummy.