Legacy code is code not under test - Michael Feathers

Legacy code is code you're afraid to change - Mark Seemann

Code where the intention isn't clear, and hasn't had any love - Anon

Code nobody wants to work on - Anon

Legacy code is code that makes you laugh and/or cry - Mark Jones

No ongoing design

No tdd

When you change the code, you can't guarantee you won't break it

The code can't be refactored

Refactoring: "disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior" - Wikipedia

changes will be harder

bug count will 

(almost certainly) increase

MORE manual testing

The code is expensive

developer optimism

technical constraints

TIME CONSTRAINTS

best practices

TDD

refactor to patterns

Keep code simple

keep code clean

Pair program

Peer code reviews

Quick hacks to get something out there - Anon

Knowingly writing bad code to deliver something on time - Anon

Stuff what's difficult or risky to change - Anon

The difference between the application that you would like to build and the application you actually build - Martin Fowler

The effort it takes to refactor your code to make it easy to add the next feature non-invasively- Michael Feathers

Haste

Long-term architectural benefits are sacrificed for expedience

apathy

Not caring about solving known problems

Narrow-mindedness

The refusal to practice solutions that are otherwise widely known to be effective

sloth

Making poor decisions based on an easy answer

Avarice

Modelling excessive details, resulting in excessive complexity

Ignorance

The result of failing to seek understanding

pride

"Not Invented Here"

improve

strangle

rewrite

replace

need time to develop clean code

need freedom to do the right thing

need to schedule tech debt payback

run the code as far as you can

break dependencies

smallest changes POSSIBLE to code

sensing variables

coverage before refactoring

prove it's worked by changing code

tests then refactor