Going to second everyone else saying “it’s not your friend’s character”. Roleplaying games have this nasty effect of attracting people that are focused on doing things “the best way” – they see the games as puzzles to solve – but what the best way of playing is is not a singular thing. And people have this weird tendency to also conflate things that seem similar.
Here, I suspect your friend is telling you that you “need” to target all of the different DCs: Fortitude, Reflex, Will, and AC. This provides you with the most flexibility as a caster, and the highest chances of actually getting the maximum effect out of your spells. Because of this, a lot of the online discussion around magic users in the game has actually focused on optimizing your ability to target all of these – because, again, the discussions are dominated by people who want to “solve” the game. But if you’re OK with partial successes and playing the character in a way that feels the most organic to you, you should do that. The game is designed so that you don’t need to be hyper-focused on optimizing your choices.
But if your friend isn’t ok with you doing that, then you should start asking them why they want to play your character for you.
S
