Apportionment

You insured the building for a million bucks, along with three of your insurance selling buddies. There was no deductible and unfortunately for you, acts of God weren't excluded. So when the Chinese satellite went ramming through the roof of the building, destroying it completely, all four of you were on the hook for that million bucks.

Well, if the apportionment described liability as "in equal parts," then each of you owe the building owner a cool quarter mill. Apportionment has different meanings as applied to real estate and other business ventures, but the gist is that when things go awry, or simply when expenses like maintenance and taxes are owed, you'll be met with the whispered refrain, "who owes what?"