Derren said:
I do not dispute that. But imo this ability should be used sparingly, only when necessary. But it looks like 4E will require that DMs use this ability whenever they want to create something which goes beyond pure combat and the DM does not want to just give the enemies a lot of magic items (which will fall into the hands of the PCs).
If every creature was capable of using Rituals, you don't need to treat this as doing something "exception" or breaking the internal logic of the game.
If rituals are balanced by levels just as everything else, the internal logic of the game tells you that it is reasonable to believe that a level 26 pit fiend can use a Scrying Ritual, or a Dragon can use a "Polymorph to Human" ritual. There are some similarities to "just" adding magical items, with the difference that they don't automatically fall into the hands of the players.
Just as with magical items, a DM needs to decide how common rituals will be in his campaigns, and how likely it is that Pit Fiends, Dragons or PCs have access to them.
In my game, Pit Fiends might not have any Rituals at all, since my story for using them doesn't require it. Except maybe one of them does know a Ritual, and its giving an edge in the hells so that the PCs will need to "investigate" (read: Kill him, and take his stuff).
In your game, most Pit Fiends might have a Scrying Ritual and a Mass Teleportation Ritual, because you want your Pit Fiends being able to watch their troops and move them quickly. It is a bit of "Mutual Assured Destruction" though, since every Pit Fiend has access to these abilities, so they rarely use it against each other. But the catch might be that one, just one Pit Fiend finds a "Divert Teleportation" Ritual, and suddenly, the balance in hell is changed, and again, the epic level heroes will have to intervene...