Are there any restrictions on mastering and/or using a ritual based on its Key Skill?

Question

I was thinking about rituals recently, and realized that I couldn't find anything restricting a character from taking rituals with key skills in which they are not trained.

Obviously there's a soft restriction there for rituals that require a skill check, as your check will be a lot lower if you're not trained, but what's stopping my psion with Arcana being the only relevant ritual skill in which he's trained from taking and using Raise Dead, which is Heal (no check), or Hallowed Temple, which is Religion (no check)?

Do the Key Skill entries for (no check) rituals actually have any purpose other than determining what variety of reagent it requires to cast?

Answer 1

No. According to the PHB ("How to Read a Ritual", p. 300), the Key Skill entry is only to describe the role of skill checks in that ritual: whether they're necessary, whether you have a choice of skills, and what reagents you need are a function of the skill chosen.

Checking the compiled errata, there are no mentions of "key skill" anywhere, so this hasn't changed since the core rules were published.

(This sounds like a good candidate for a house rule.)

Answer 2

The ritual system of 4e has a lot of implications for a campaign setting. If played by the books low level useful magic is not unusual and would be one of the hallmarks of the nobility and upper middle class given the cost. Those are backed by major organizations have a huge advantages as they can use Leomund's Secret Chest and maintains the teleportation circles used by Link Portal.

Lord: Banford, cast phantom steed for all of us. We need to get a move on to the western palace. Banford: Yes my liege.

Requiring that only trained skills can use the ritual isn't going to solve the problem. On the player end they will just funnel their money through the cleric or mage that can cast the ritual. If a player wants to slot the feat, and deal with rituals; let them. That problem pales against the larger implication for the setting.

Fortunately the problem is easy to solve by changing the list of the known rituals. Look over the list carefully and think about how the king, church, guilds and yes, players would manipulate this and ask whether is this part of your setting. If there is a problem modify it or remove it from your official list.