Questions frequently need tweaking to the rules, even after going through the sandbox. However, rule changes that break previously valid answers are annoying to the answerer (at least from the perspective of someone who's had answers 'broken' on several occasions).
Example rule changes, (from least to most annoying):
- Removing a rule
- Closing a small loophole soon after the question was posted
- Closing a loophole used by existing answers
- Tighter restrictions on input/output format that break existing answers
- Adding a rule to "make it harder" after answers have been posted
- Completely changing the question because the original was just simply too easy (this happened today)
Can we come to a consensus on what rule changes are acceptable, and what should be avoided? I realize this is subjective, but a good guideline would be useful.