This is one of those encounters that starts off comical, but gets real serious when the little mudmen get involved. Those things are no joke.
This adventure speaks to the kid in my heart. Buried treasure. I always, always loved a good story where the protagonists are scrapping at the earth trying to reveal the mysterious treasure beneath.
The mysterious treasure beneath is a skull that allows a spellcaster on additional spell slot per day. I did not write what spell level that slot could be.
GM Advice on the Adventure: A GM could easily just allow the spell skull a 1st level spell slot. Myself, I consider it a minor artifact. It's a huge help to the spellcaster without being overpowering. And it has a drawback with the possibility of summoning a skeleton. To put a twist on this, what level of spell cast when using the skull would be the HD of the skeleton summoned. Swords & Wizardry Light is a low-level system meant for players to grind out adventures. I think the spell skull is a good balanced item for the system and its power can grow with the character.
I hope you enjoy this little encounter. It was brought about by my attempt at a side view map. I am practicing to improve this view. I love the cutaway maps that Dyson, Forster and Jackson draw. I need to up my game!
And if you are wondering why Cross-Eyed Louie is digging for the skull you just imagine Louie giving you the cross-eyed stink eye and he says, "I digs for treasure, cause I digs for treasure. No more explaining than that. Hear?"