Wyszkowski's Second Law

Anything can be made to work if you fiddle with it long enough.

Law of Selective Gravity

An object will fall so as to do the most damage.

Jennings' Corollary: The chance of the bread falling with the butter side down is directly proportional to the value of the carpet.

Law of the Perversity of Nature

You cannot successfully determine beforehand which side of the bread to butter.

Shaw's Principle

Build a system that even a fool can use, and only a fool will want to use it.

Lubarsky's Law of Cybernetic Entomology

There's always one more bug.

First Law of Revision

Information necessitating a change of design will be conveyed to the designer after - and only after - the plans are complete. (Often called the 'Now They Tell Us' Law)

Corollary : In simple cases, presenting one obvious right way versus one obvious wrong way, it is often wiser to choose the wrong way, so as to expedite subsequent revision.

Second Law of Revision

he more innocuous the modification appears to be, the further its influence will extend and the more plans will have to be redrawn.