Export data for use in another game.
Probably characters for a sequel, but any type data counts.
The first video game about Export data for use in another game. was released in 1987.
For what is exported/imported, see data import tag, since it's likely the target game of the data transfer is what decides what data is used and what isn't, not the source game. Source game may have impact on this in older systems where you specifically need to export the data to some storage medium. Usually we can assume that the game that imports the data reads the data from some shared save location, such as a memory card on consoles, from hard drive on PC (Windows, Linux, Mac, etc.) games and so forth.
Companion tag: dataimport