The rules will be similar to the usual rules of the IPT (see IPT website: https://iptnet.info/official-rules/) that in short are also presented here on the website of the GPT (https://germany.iptnet.info/rules/).
For example, there is a simplification on what problems can be challenged: Each team has to announce which problems it has worked on (probably at least one problem per participant). Only these problems can be challenged by other teams and the team can only report on the problems that it has announced. Therefore, to participate, it is sufficient if every participant works on one problem.
Furthermore, participants of the Online-GPT are allowed to present their problem again in the physics fights of a qualifying GPT (with a maximum of two Online-GPT-problems per team).
Based on the experiences with the Online-GPT 2020 further modifications have been proposed: First, in the first physics fights the role of a reviewer might be skipped in order to speed up the physics fights. In the final the role of a reviewer probably will still be used. Second, technical timeouts might be introduced. A decision about these additional modifications will be communicated to all participants of the tournament.
The rules can be downloaded here or below.ruleset