I'd like to know why this game does'nt give you the option of choosing DX modes?, like I'm playing legendary edition and Its in DX9 mode in Windows 7. Now I know this is a cross platform game and that could be part of the reason, but I've played games before on PC that are cross platform and they have had options of choosing between DX9, 10 & 11 on PC. Is this a limitation of the engine? Thanks in advance.

What version of directX is available to you is based on your graphics card. Each version adds new features and possibly performance upgrades. To maximise the potential audience, choosing to use a lower version means the likelihood of more consumers being able to play your game because more lower grade graphics card can supported.

So the game engine can easily allow detection of different versions, its just a few lines of code. However to take advantage of new features introduced with each version you would need to code in things to work with those. This would mean that the experience would be different depending on what your graphics card is. Additionally extra work for the developers to support the differences depending on why features you have.

Have a read of this as there are a few good explainations - http://gaming.stackexchange.com/questions/7829/whats-the-difference-between-directx-10-and-directx-9

Yes, Skyrim's engine is limited to DirectX 9.0C functionality.

Thanks, seems odd considering this is 2011 release game.

Yes, I understand that. Using Radeon HD 7870 OC edition atm, its a shame one can't use higher DX modes than version 9C, the visual quality is let down to some extent in an otherwise great game.