The Ladder system comes with several different variants and is available for players to play again or play for the first-time, depending on whether they have played the Diablo II in the first place Diablo II or not.
If you did play the game that was the precursor to the remake, then you'll be pretty familiar with some of the key features of this Ladder system. It's offered in Classic, Hardcore Classic, Expansion, and Hardcore Expansion variants with each of them having different rules governing how many lives players have , as well as the content available.
"Each modes will be equipped with their own leaderboard that allows players to strategically gain experience within an allotted time frame while also having access to specific content for Ladder," Blizzard's announcement about the introduction in the Ladder feature in Diablo II: Resurrected said. "When this Ladder season concludes D2R Items for sale, leaderboard rankings will be reset by transferring characters into non-ladder modes, giving players the opportunity."