The dataset contains all instances that the organizers of the competition received or collected during the preparation phase of the Model Counting Competition 2020. The dataset includes short benchmark descriptions (00_description.{pdf,txt,md}) by the submitters/collectors (00_authors.txt). For a more details, we refer to the reportFichte, Hecher, Hamiti: The Model Counting Competition 2020. -----Changelog: 2023-10-17 (v2): We updated the instances to the most recent competition format in preparation for the report on the competitions 2021-2023. Note that the old instance set contained various instances with incorrect headers (less variables or clauses than in the actual data), unterminated lines, or a few broken lines. We corrected these instances by scripts that are available on github (daajoe:mc_format_tools).