Epic Games have just released the first Preview version of Unreal Engine 4.26. UE4 preview 1 releases are extremely important as they highlight the new features that you can expect in the final 4.26 release, as well as adding several new experimental features. Unreal 4.26 is no exception, with the biggest new feature being the fact the Chaos Physics and Destruction engine is now enabled out of the box replacing the existing PhysX physics, although the new experimental water system taken from Fortnite is a close second.
EDIT – On further exploration, it would appear the Water plugin never made the preview 1 release and hopefully will arrive in preview 2.
Details of the release from the Unreal Engine blog:
Experience the latest features coming to Unreal Engine with Unreal Engine 4.26 Preview 1—available now.
Test drive the production-ready Chaos Physics and Destruction System—the now default physics system—and take the new experimental Chaos Vehicle system for a spin. Virtual production pipelines also receive a boost with added movie render queue controls, Sequencer updates, and DMX improvements. If that’s not enough, check out the brand-new water system, the Chaos Ragdoll system (beta), production-ready hair and fur, and more!
You can learn more details about the release on the Unreal Engine forums. While Chaos is now enabled out of the box, it isn’t immediately obvious how to get started using Chaos Physics and Destruction. Therefore in the video below, in addition to covering what is new in the 4.26 release, we also have a getting started with Chaos tutorial to get you up and going quickly.