Patch 1.0.X are all patches beginning with 1.0.
1.0.2 (1.0 was never released) was the initial retail version of Crusader Kings III and was released on 2020-09-01 with the checksum SOHY.
1.0.3 was a bugfix released on 2020-09-03 with the checksum 935c.
- Rewrote the order of succession system. This fixes a variety of issue related to succession. Some examples include half-siblings from the wrong parent inheriting, distant relatives not inheriting, and some issues with who would inherit land in partition.
- Forum, Patch 1.0.3. Out now! Checksum [935c], 2020-09-03.