[Careful: there are two similar games with Entdecker in the title. Don't confuse Entdecker with Die Neuen Entdecker (also known as Entdecker: Exploring New Horizons), a different game. In short - if your Entdecker's board has a scout trail leading to native huts, it's not this Entdecker.]
Entdecker starts with a blank game board that represents an unexplored sea. Tiles are drawn and placed on squares on the board. As the tiles are placed islands develop on the board and players pay to place settlements, bases, or scouts on these islands in an effort to become the most powerful discoverer of all. Completed islands yield victory points to all who have invested in exploration on an island, but of course the most points go to the player who has established the strongest presence.
These are the rules for Entdecker with the Mark E Johnson variant integrated into the text. The original rules are in the text, just stricken and the variant rules noted in blue. If you don't mind small text, the best thing may be to print this 2-up double sided on a single letter sized sheet.
Thanks to Mark and Mike Siggins (original translator) for giving me permission to upload this!