Shillelagh and other spellcasting stats

So there are several ways to get the Shillelagh spell, many of which allow you to select the stat you use to cast it.  Many are straight forward, the feat lets you pick it when you select it now, you can pick it up through a Warlock pact, bards and their spell stealing ways.  So I come to Barbarian or Pugilist.  Both have subclasses where CON is their spellcasting stat.  Can you use Shillelagh with CON?

It seems unlikely in WotC material, but if you're including third-party classes and subclasses, then probably.

(You could always just homebrew such a subclass yourself, after all, though it may not work on DDB.)

Quote from Hedd666 >>

So there are several ways to get the Shillelagh spell, many of which allow you to select the stat you use to cast it.  Many are straight forward, the feat lets you pick it when you select it now, you can pick it up through a Warlock pact, bards and their spell stealing ways.  So I come to Barbarian or Pugilist.  Both have subclasses where CON is their spellcasting stat.  Can you use Shillelagh with CON?

The feature that grants you the spell tells you what spellcasting ability you're meant to use for it. If it says the spellcasting ability is Constitution, then that's what you use, odd as it might sound.

The Pugilist's spellcasting subclass can't grant you Shillelagh, though, since it's not on the Warlock list. If you're a Pugilist with that subclass, but you're getting Shillelagh from some other source like a feat, you use the spellcasting ability specified by that other source, not Constitution.

There aren't any official Barbarian subclasses that use Constitution as a spellcasting ability, but perhaps there's something in a third-party source. If there is, and it can grant you the Shillelagh spell with that spellcasting ability, then that's what you use.