10. The end justifies the means only when successful.

Handicapping one’s own capabilities by focusing on a singular strategy may lead to the downfall of lesser players, but veteran players will have bargained that handicap to obtain a “win” scenario.  Whether it be sacrificing ones own defence to press an attack on an opponent, spending vast quantities of economy on a hoard of highly effective units, using an army to force an opposing army to concentrate and nuking both, or any other seemingly hopeless activity; if it succeeds, then it was time and effort spent on a correct strategy.