Rebalancing Spellcasting 5e

[terodil]

I don't have all that much time at the moment, so I'll just focus on one element that does re-occur several times in your argument, and that's the point of 'if it doesn't matter [e.g. because there is no appropriate spell, the spell fails or anything else], the change doesn't have any impact'. That's not true, I think. It makes the caster feel even ****tier; it's not just the strategic failure of picking a bad spell for the encounter, e.g. due to lack of foreknowledge, or the operational failure of having a suitable spell fail entirely -- now the caster has to pay an extra penalty on top because it could potentially have been a good spell, saved for the right time, that was 100% effective. If I was a caster, I would feel very demotivated by this. YMMV.