RPG Maker VX Ace doesn't allow for out-of-the-box manipulation of random encounter probabilities, so I had to write a custom Ruby script for my game that manipulates the current map's encounter table in the memory after each battle. I then discovered during playtesting, that this table is reset every time you re-enter the dungeon, so I had to move the code to a common event with two separate triggers, which would be carried across locations, which was a lot of ugly code, but it worked. I have since made the code much more elegant, and it will be included in the post-rating period re-upload...
Viewing post in What was the hackiest thing you did during the game jam?
There's something so satisfying about cleaning up a hacky solution... we've got a laundry list of fixes and quality-of-life improvements for our next build. We somehow managed (largely due to our very talented programmer) to not have too much spaghetti, but there's certainly some err... sub-optimal ways I handled branching dialogue in our game behind the scenes.