diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index c9f6faa..8a432b1 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -9,6 +9,14 @@ Baseline rules for patch submissions are as follows. Any patches violating the r
 * For a new game that was never supported (not a new version of a game, but rather a new series): please wait 1 year after official AC release in Japan.
 * For new version of an already supported game: proceed with caution and use generally-accepted community guidelines.
 
+### Avoiding regressions
+
+The biggest risk in making code changes to spice is the risk of regressions. There is a **lot** of shared code used by many different games, reaching back game versions that are more than a decade old. It is practically impossible to test all supported games and versions.
+
+Additionally, there's a lot of code that get exercised on specific hardware - including hardware that you probably don't have access to (e.g., ICCA reader, real cabinet I/O, specific brand of touch screens...)
+
+Therefore, when making code changes, please by extremely careful about containing / scoping your changes. Make targeted bug fixes scoped to handful of game versions and hardware configuration. When adding new features, make it off by default, unless there is a really good reason to make it the default. If you make a new default, add an option that disables it so that users can opt out as needed.
+
 ### Code quality requirements
 
 * Test for regressions, at least in and around the component you are modifying: