Warner's engineers took it upon themselves to design a disc that can be encoded with a combination of DVD, HD DVD or Blu-ray. These discs, something that Blu-ray and HD DVD developers have said was difficult, if not impossible to make, will take the pressure off consumers on having to decide which format they have to buy.
The hybrids work by having HD DVD players read through the 0.1mm Blu-ray layer to the 0.6mm HD DVD layer. As far as the player knows, the disc is just a plain old HD DVD. Blu-rays will just read the 0.1mm layer and ignore the other. Plus, a regular DVD can be pressed on the reverse side, allowing users to flip over the disc in case they want to play it in an older machine.