Margin of error. In financial matters, this can be savings or a relative lack of leverage. In planning, this can be extra time for unforeseen circumstances. In

Margin of error. In financial matters, this can be savings or a relative lack of leverage. In planning, this can be extra time for unforeseen circumstances. In construction of buildings or software, it is that little over-engineering that saves you when people do unexpected things with what you built. The general principle is never to go all out and gain the maximum efficiency, for then you lose the slack you will need when something unexpected inevitably happens. Even the best can so easily lose themselves in competitions where their desire to win drives them to take unwise risks and forego a reasonable margin of error. This is not so much a force multiplier that people don't know about, but more one that they disregard because it never seems important until you need it.