Fifty/fifty is splitting dating costs and effort evenly so neither partner carries more than the other.
Fifty/fifty in dating means dividing expenses and responsibilities equally, so each person pays their half of dates and contributes the same effort.
In practice it looks like splitting the dinner bill, taking turns planning outings, or alternating who treats. People choose it to keep things fair and free of obligation.
It often comes up in debates about who should pay, and it overlaps with discussions of emotional labor and shared load.
There is no universal right answer, only a shared one. Talk early about how you both want to handle money and effort, since matched expectations prevent quiet resentment later.