As for stoneskin, I understand that one. There’s no simple debuff like accuracy of EV that’d work because ultimately, it’d still either be worth casting all the time or none of the time. Adding Ponderousness to it would be cool, and a nice parallel to swiftness (same level spell, and you could give it the exact same magnitude of change), but again if you were planning to stand your ground optimal play would always be to cast it. Which is why I don’t think the Ozocubu change will work.

Speaking of Ozocubu, that one seems like a good candidate for the repel missiles treatment, since fire attacks already break it in some fights. I think both it and Stoneskin might be ok melee buffs if they were permanent but borrowed that “lowered casting success” penalty from some transmutations, and fizzled if you tried to switch to heavier armor than you cast it in.

Additionally, certain effects or types of damage might have a chance to interrupt your concentration, causing the buffs to be dropped. This would be a nice addition for combat with enemy spellcasters, as well. They would have to re-up their spells, risking valuable MP and a turn.

Have buffs reserve max MP, consuming more % based on the current fail rate of the spell

Anyway, thanks for making things clear, I guess I’ll just have to deal with it somehow.

Having maxMP costs on buffs would not lead to interesting decisions, in our assessment. The goal of design is not to provide as many options to the player as possible, it is to step up and provide what we think is a get set of options. Buff spells are very problematic from various points of view (the posting did not even mention all of them), and we’ve outlined why we did what we did.

All other questions you pose have better answers in gameplay than the one about maxMP cost on buffs. Seriously, it’s been contemplated for years and will not happen.

Stoneskin: Increased AC with decreased EV. Character suddenly gets tougher skin, but doesn’t quite feels as nimble.

CS: Apply some form of spell penalty/weapon delay as with normal shields. The shield would require some sort of passive concentration meaning you wouldn’t be as focused on other spells and weapon use

Phase shift: If hit, remove EV bonus and take minor irresistable damage. Making contact with reality pulls you back to this dimension somewhat violently.

If someone comes up with some really genius ideas, we can always add the spells back, of course – it’s quite easy. But we go to design with the ideas we’ve got, as the famous saying probably goes.

Stoneskin, Condensation Shield, and Phase Shift are removed because… that approach to rehabilitating them wasn’t possible?

I would like to have seen the rationale for why the game would be better off without these particular spells compared to tedium-free modifications of them.

The way you put it, we could never change anything, because everything had some purpose.

Of course, you’re also exaggerating. It is perfectly possible to win “pure” casters in any DCSS version without using buffs.

I also agree with your reasoning. A real choice is always more interesting than a fake choice, in rogue-esques and otherwise. DCSS has always been a prime example of a well made, thought out and balanced specimen in the genre, and this post is testament to that. Keep up the good work.