The 2018 rule five draft is scheduled for Thursday, December 13th at the MLB winter meetings in Las Vegas, Nevada. For a thorough explanation of the rule five draft, here is a good site. In short, the Dodgers have a handful of prospects in their organization that they must add to their forty man roster by Tuesday or teams can select them in the rule five draft.
If a Dodger prospect is picked in the rule five draft, then the opposing team must keep them on their active big league roster for the entire 2019 season or they have to be offered back to the Dodgers.