You're White, you have a chessboard and a set of chess pieces, your opponent has their own chessboard and pieces and plays black. You sit back to back. An umpire lets you know when your opponent has moved, if there is a capture or a check, and keeps a score. And that's more or less it!
You really have to make sure you prepare your attacks, and make sure everything is safe before you launch. Here are a couple of example games, one played at our club earlier this evening, one played in 1971 in Cincinnati.
[Event "Kriegspiel"]
[Site "?"]
[Date "2012.??.??"]
[Round "?"]
[White "Cody"]
[Black "Taylor"]
[Result "0-1"]
[ECO "A40"]
[PlyCount "66"]
1. d4 ({First attempt. (Before this game, I re-stated the most important thing
in Kriegspiel - make sure everything is defended!)} 1. e4 1... e5 2. d4 Nf6 3.
dxe5 3... Nxe4 {So, that's two totally undefended pawns taken by move 3!} 4.
Bc4 Be7 5. Qd5 Nc3 (5... O-O {would have been interesting:} 6. Qxf7+ Rxf7 7.
Bxf7+ Kxf7) 6. Qxf7#) 1... e6 2. Nc3 d5 3. Nf3 c5 4. Nxd5 exd5 5. e4 cxd4 6.
exd5 Bb4+ 7. Bd2 Bxd2+ 8. Qxd2 8... Nf6 {
I think Black has the position correct at this point.} 9. O-O-O {
You have to play a move like this very quietly...} 9... Qe7 10. Qa5 Qd6 11.
Qb5+ Bd7 12. Qe2+ Kd8 13. Re1 g5 14. Qe7+ Qxe7 15. Rxe7 Kxe7 16. Bc4 Bb5 17.
Re1+ Kd8 18. b4 g4 19. a4 19... gxf3 {Now White tried b5, was told 'No'.} 20.
a5 (20. axb5 $1) 20... Rg8 21. Bxb5 Rxg2 22. a6 Ng4 23. Re8+ Kc7 24. Rh8 24...
Nxf2 {Hoping to checkmate the King on h1!} 25. Ba4 bxa6 26. b5 Rg1+ 27. Kb2 Ne4
28. Rd8 f2 29. Rd7+ Kc8 (29... Kxd7 {
was worth a try! The worst that can happen is, you are told 'No'.}) 30. Rd6
f1=Q 31. b6 Qb1+ 32. Ka3 Qa1+ 33. Kb4 Qc3# 0-1
A game played by more experienced players. Notice how White carefully prepares every breakthrough - good chess strategy too!
[Event "Kriegspiel, Cincinnati"] [Site "?"] [Date "1971.??.??"] [Round "?"] [White "Hayes, Rea"] [Black "Juhasz, Mike"] [Result "1-0"] [ECO "A02"] [PlyCount "111"] 1. f4 f6 2. Nf3 c6 3. g3 Kf7 4. Bh3 e6 5. O-O b6 6. c3 Bb7 7. a3 g6 8. b4 h6 9. Bb2 Bg7 10. d3 d6 11. Nbd2 a6 12. c4 Qe7 13. e4 Nd7 14. d4 Rd8 15. Re1 Rh7 16. e5 dxe5 17. dxe5 fxe5 18. Nxe5+ Nxe5 19. Bxe5 Bxe5 20. Rxe5 c5 21. bxc5 bxc5 22. Qe2 Ba8 23. Re1 Rc8 24. Bxe6+ Qxe6 25. Rxe6 Bg2 26. Re5 Bh3 27. Ne4 Bd7 28. Rd1 Rc6 29. Rdd5 g5 30. fxg5 hxg5 31. Qf2+ Kg6 32. Nxc5 Rxc5 33. Rxc5 Rxh2 34. Qxh2 Be6 35. Ra5 Kf6 36. Qd2 Bf5 37. Qd5 Ne7 38. c5 Bc8 39. c6 Bh3 40. Rc5 Bc8 41. Qc4 Kg7 42. c7 Kg6 43. Rxg5+ Kf6 44. Rgd5 Ke6 45. Qd4 Nc6 46. Rd8 Bb7 47. c8=Q+ Ke7 48. Qf4 Bxc8 49. Rxc8 Nd4 50. R5c7+ Ke6 51. Rc6+ Nxc6 52. Rxc6+ Kd5 53. Qc4+ Ke5 54. Qe6+ Kd4 55. Rc4+ Kd3 56. Qe4+ 1-0More?