Apparently the guys from Pearl Abyss have launched a campaign by which complete the pre-registration for Black Desert Mobile they give you an access key for the version of PC and consoles.
And I say it seems because the promotion is not well explained in any official site that I know of. I invite you if you want to test and share the results with the rest of the community. The promotion appears to be active for EU/NA servers and also SA on PC:
Black Desert Mobile global launch
Recently Black Desert mobile was released in the form of soft-launch in a few countries selected. The official global launch is announced for the month of december.
*Thanks Neku-Kun for the notice