An ambitious project and once finished a perfect base for highly costumized metin2 servers.
GameForge is a german company, thus I assume they would take legal actions against any unprohibited distribution of their product in front of a german court.
What I would like to mention is a part out of the Act on Copyright and Related Right (Urheberrechtsgesetz – UrhG).
As far as I understand, the final product of the above metioned project would be a copy of the game metin2. In our case, we cannot (even) bring to proof that we own a licence or any other evidence in which a right to reproduce, alter or copy the original game is metioned. Rewriting the code base would only make all participans to authors of their code base, but put together with GameForges assets we would have an altered product. Altered on the code side.
Translations and other adaptations of a work which are the adapter’s own intellectual creations are protected as independent works without prejudice to the copyright in the adapted work. The insubstantial adaptation of an unprotected musical work is not protected as an independent work.
The author is the creator of the work.
Access to copies of works
(1) The author may require that the owner of the original or of a copy of his work make the original or copy thereof available to him insofar as this is necessary for the production of copies or adaptations of the work and does not conflict with the legitimate interests of the owner.
(2) The owner shall not be obliged to surrender the original or the copy to the author.
Infringement of rights
(1) The rightholder may require of the owner or proprietor that all unlawfully produced or distributed copies or all copies intended for unlawful distribution be destroyed. Section 98 (3) and (4) shall apply accordingly.
(2) Subsection (1) shall apply accordingly to means the sole purpose of which is to facilitate the unauthorised removal or circumvention of any technical device which may have been applied to protect the computer program.
Prohibition of exploitation
(1) Illegally produced copies may neither be distributed nor used for the purposes of communication to the public.
Right to require cessation of infringement and to damages
(1) Any person who infringes copyright or any other right protected under this Act may be required by the injured party to eliminate the infringement or, where there is a risk of repeated infringement, may be required by the injured party to cease and desist. Entitlement to prohibit the infringer from future infringement shall also exist where the risk of infringement exists for the first time.
(2) Any person who intentionally or negligently performs such an act shall be obliged to pay the injured party damages for the prejudice suffered as a result of the infringement. When setting the damages any profit obtained by the infringer as a result of the infringement of the right may also be taken into account. Entitlement to damages may also be assessed on the basis of the amount the infringer would have had to pay in equitable remuneration if the infringer had requested authorisation to use the right infringed. Authors, writers of scientific editions (section 70), photographers (section 72) and performers (section 73) may also demand monetary compensation for damage which is non-pecuniary in nature provided and to the extent that this is equitable.
P.S: I am not a lawyer