In pondering "systems that went wrong", I've noticed certain patterns in how they go wrong and patterns in the symptoms. I'll propose a UsefulLie dichotomy between idealistic messes and "lazy" messes.

Idealistic, GoldPlating, and MentalMasturbation messes:

* Difficult to figure out what any piece of code does
* Difficult to trace the impact of a change due to too many layers of indirection
* Wrong abstraction used, resulting in big DiscontinuitySpike''''''s. Some changes that fit the abstractions are quite easy, others are nearly impossible.
* Unlike lazy messes, you spend more time studying code than typing code to fix it.
* Inconsistent use of different paradigms or techniques.
* Lots of wasted code for dead-end or unfinished concepts.

Lazy messes:

* Lot's of violation of OnceAndOnlyOnce, so prepare to type a lot to change or fix.
* Generally a consistent pattern
* Lots of code to do relatively little
* Lots of similar-looking IF statements or viney, repetitious sub-classing for endless exceptions to the rule.