I have been told by a friend who is a player that you can get to level 100 but no higher. Is this true? I'm aware from reading the official Game Guide that it is impossible to get all perks to 100 but is it true that there are only so many levels you can get to before it stops levelling up your character?

The latest patch eliminated the level cap by allowing you to reset skills back to 15. Skills still and always will have a cap of 100, but your overall level is uncapped. Basically allowing you to get unlimited perk points, and there by all the perks.

However, as far as gameplay goes, the general average level people are "done" leveling at is around 50. The guide you have was probably the origional which was made before the cap was removed.

Ah, right. So it IS possible to get all perks to 100 eventually, but from around level 50 overall it's generally much harder to level? Interesting. Thank you for the info. I HAVE noticed it takes a little longer to level up each time. I think the game would be slightly more fun if you also came closer to levelling up when you've completed a task, which doesn't seem to happen. That would make more sense than getting nothing for it, level wise.

As Echonite said, it possible to past the level cap of 100 by making skills Legendary.