Rules:

• Everything needed to play the game must be able to fit in a mason jar (including dice, etc). Please include an example photo of the assembled game and some brief instructions on how to assemble it if it might be unclear.
• I don't know if mason jars are different in different countries, I believe 16 ounce (490 mL) mason jars are standard here. Please indicate the size of the mason jar you use if it's a different size; a smaller jar might be fun. Likewise, if mason jars are not prevalent where you live, you can substitute a similar reusable container intended for storing food.
• Include safety tools and content warnings as appropriate.
• Like all the other game jams I've seen I reserve the right to remove bigoted content etc.
• This is intended to be for TTRPGs, although if you can make a game that runs on a very small, possibly cylindrical computer that counts.
• You are not required to boil the game or seal it in the jar, although if any portion is edible, keep food safety in mind.

Bonus points (although this is an unranked jam with no points):

• While a 1 page game and a pair of dice technically count, you are encouraged to cram as many things into the mason jar as possible.
• Try not using any content external to the mason jar including game rules, other than safety tools like the TTRPG safety toolkit.
• Try incorporating the jar as a part of the game itself.

Image is CC0, from here: https://www.pexels.com/photo/blur-focus-jam-jars-48817/