If you've been waiting to take advantage of the real-time ray tracing effects on your flashy new RTX graphics cards, good news: as of today games will be able to officially take advantage of them. Slightly less good news: only one game so far can actually do that.
A blog post on the official DirectX Blog notes that the October 2018 update will have standardised support for DirectX Ray Tracing, enabling games to take advantage of the hardware on Nvidia's RTX cards for real-time ray tracing.
Only three games will support the API thus far, two of which aren't out yet: Metro Exodus, Battlefield 5, which doesn't launch until mid-November, and Shadow of the Tomb Raider. Each game will use ray tracing differently, with Tomb Raider adding more realistic shadows, Battlefield 5 deploying ray traced reflections, and Metro Exodus using ray tracing for improved ambient occlusion and global illumination to create more natural lighting.
It's also worth noting that Shadow of the Tomb Raider doesn't currently have ray tracing support either. The developers posted that ray-tracing tech would be added to Lara's latest adventure "in a post-launch update", but that doesn't appear to have been pushed live yet.
The ray tracing support within DirectX comes with the October update of Windows 10, which went live to all users from today. That patch is usually rolled out in stages, but you can speed up the process by installing it forcibly here. (It'll also save you the surprise of having a gargantuan Windows update when you restart sometime this month.)
It comes days before the RTX 2080 is due to ship, according to the latest date on the GeForce website. The RTX 2070, meanwhile, will be available internationally from October 17. The Founders Edition will cost $899 in Australia, but non-Founders Edition boards aren't available as of yet.