Does casting Contingency with Wish allow you to pick a spell that you don't usually have access to as the contingent spell?

Question

One of the clauses of the contingency spell is that the contingent spell must be a spell "that you can cast".

The wish spell allows you to cast any spell of any class (except other 9th-level spells), so if you know wish, you technically "can cast" most spells.

Let's say that Bobby the 17th-level sorcerer wants to cast Otiluke's resilient sphere as a contingency, and he uses wish to cast contingency. Could he then pick the sphere as his contingent spell (expending a 4th-level slot in the process as per the spell), considering that he can't normally cast it (as it's not on the sorcerer spell list) but has the ability to do so with wish?

Answer 1

No, because casting Wish is not casting the other spell.

Wish duplicates a spell of 8th level or lower (when used that way). It does not cause you to cast Otiluke's Sphere; you cast Wish, and the effect of Otiluke's happens. You are still unable to cast spells that aren't on your spell list.

Answer 2

No, Wish does not CAST the other spell but rather recreates the effects.

Contingency states:

Choose a spell of 5th level or lower that you can cast, that has a casting time of 1 action, and can target you.

Wish states that you can use it to:

...duplicate the effect of any other spell of 8th level or lower. You don't need to meet the requirements of that spell, it simply takes effect.

Note the specific wording: Wish does not allow you to CAST any spell of 8th level or lower but to RECREATE THE EFFECTS of any spell of 8th level or lower.

This doesn't meet Contingency's requirement of "A spell you can cast" since you aren't casting the spell via wish but recreating the effect of said spell.

Now, if the Caster knows Wish, they could Wish to create a spell identical to Contingency, but instead of Contingency triggering a spell effect it triggers a certain pre-defined effect. Effectively you could use Wish to create your own spell, although this forces you to chance the 33% odds of never being able to cast Wish again. Your DM can also yes/no this as they see fit.

Answer 3

No: "can" is present tense

The "can" in "can cast" must refer to at the time of the casting. It is in the present tense. It doesn't mean you could cast it after you've gained another level and select it as a new known spell, or that you will be able to cast it once you get your hands on a magic item that allows you to do so: you must be able to cast it at the time you cast Contingency. With that in mind, consider these two problems.

1.) As Mark Wells pointed out, Wish doesn't "cast" a lower level spell: it creates its effects. So Otiluke's Resilient Sphere isn't a "spell you can cast", it's a spell you can emulate. This is similar to the way that a fighter who could drink a Potion of Heroism could be under the effects of the Bless spell, but can't cast Bless.

2.) Even if Wish DID cast the lower level spell (which it doesn't), you wouldn't be able to cast Otiluke's Resilient Sphere without casting Wish again. And to do that, you'd need a second 9th level spell slot, since you're already spending one on creating the effects of Contingency (via Wish). A 17th level sorcerer has only one 9th level spell slot per day (and can't create more with sorcery points). So at the time of casting Contingency, Otiluke's Resilient Sphere isn't a spell you "can" cast.

An argument could be made that you also can't do what you propose because Wish is a 9th level spell, and Contingency can only line up a spell 5th level or lower. But that argument is complicated by the precise wording of Contingency, so I'll leave it alone for now. Regardless, these two reason (especially the first one) are barrier enough.