One of my favorite magic items to give players. I don't remember which DM I stole it from, but it's so fun. I don't remember the precise wording but it's something like
All or Nothing Coin
While in possession of this coin you may choose to expend one charge to replace your d20 with a coin for your next attack, save or check. Treat a heads as a natural 20 and a tails as a natural 1.
The coin may hold a maximum of 4 charges at time. At dawn all charges are either depleted or restored (determined by coin flip)
You might be interested in “rolling with emphasis”, a house rule by Brandon Lee Mulligan. Rather than rolling twice and taking the best/worst result, you take the result furthest from 10. Designed for actions that can only end really well or really badly.
Love how most of the comments imply GO WATCH IT NOW but I totally agree, a classic, see if you can find the implied sex/blowjob (you probably can and yes children watched this movie)