The vm.max_map_count sysctl value controls the operating system limits on the maximum number of memory map (mmap) areas that a process can have. 
While Tumbleweed defaults to of ~65k for vm.max_map_count and matches that of many other OS defaults, SteamOS for e.g. ships with a value of 2147483642.

Most software doesn't use too many mmaps that the 65k default is suitably for the vast majority of user-space software out there. But in particular for a few and unfortunately increasing number of Windows games running on Linux via Steam Play (Proton), that limit can actually be exceeded. Among the known games needing a higher memory map limit are DayZ, Hogwarts Legacy, Counter Strike 2, and others. 


-Fixes some newer video games, as mentioned in https://www.phoronix.com/news/Fedora-39-Max-Map-Count-Approve

-Without this you will experience crashes on some newer games. (Hogwarts Legacy, Etc..)

The easiest way to "fix" this is to add a drop-in conf file into 
/usr/lib/sysctl.d/ with the desired (higher) value.

Kernel Docs: kernel.org/doc/Documentation/sysctl/vm.txt
SUSE Support: suse.com/support/kb/doc/?id=000016692