Blood Pact

The Blood Pact is a contract made between the leaders of two respective countries. Often, it is used by one country to manipulate another and force the other to do their own bidding. If one leader breaks the contract, he lays a curse on his country until the pact is destroyed. The curse kills one person the first day, two people the second day, four the third, eight the fourth, sixteen the fifth, etc.

The effect of the blood pact can only be reversed one way- The leaders are killed and the contract itself is destroyed.

It appears in the Fire Emblem series.