Force multiplication, in military usage, refers to an attribute or a combination of attributes which make a given force more effective than that same force would be without it. The expected size increase required to have the same effectiveness without that advantage is the multiplication factor. The source of the increase is the Force multiplier.
In Technology terms, if a certain technology like GPS enables a force to accomplish the same results of a force five times as large but without GPS, then the multiplier is 5. Such estimates are used to justify an investment cost for force multipliers. A force multiplier refers to a factor that dramatically increases (hence “multiplies”) the effectiveness of an item or group.

Some common force multipliers are:

Some factors may influence one another, e.g. enhanced technology improving morale or training improving reputation.

It seems clear that force multiplication existed before anyone had a name for it. While the Mongols used swarming tactics coordinated by non-electronic communications, such simple tactics nevertheless made them notably effective. In the Middle Ages, stakes were often driven into the ground to protect archers. This is an example of “combined arms,” a doctrinal development and another example of force multiplication.