It's against the rules in DnD, sure.
But does it really make that big of a difference? If you play a Wizard, and I play a Sorcerer... I don't feel like you're overpowered. You're spending a lot of money on scrolls, most of which you'll never get around to memorizing because your active list is limited and tends to be filled up with favorites.
Meanwhile, I'm over here twinning and quickening spells and basically wrecking house.
Shrug. I guess it just doesn't bother me that Wizards can learn Cleric spells. In fact, I kind of think the Wizard needs it to compete with other classes.
I'm inclined to agree.
Just because a wizard can theoretically duplicate the role of a cleric using learned spells doesn't mean it's exploitative to do so, or that anyone actually will. You sacrifice the wizard's other utilities to do so. Maybe the ramifications are more egregious later in the game when the wizard has more spell slots and active spells, but just looking at the first four levels, it's more of an expensive novelty that is contrary to lore than anything. That being said, I rather enjoy being a 'spellbook completionist' when I play a wizard, even if I don't use the spells.
