D&D (2024) Spells versus Rituals

[tetrasodium]

You can have rituals that aren't spells already- in fact, there are a number of them in published 5e adventures, such as the yuan-ti ritual to create histachii in Tomb of Annihilation. But allowing certain spells to be rituals as well as being available for casting on the spot with spell slots is a good thing, IMHO.

I don't agree with Yaarel very often, but in this case I think there is agreement with his OP. This doesn't look to be quite what he's talking about though, especially after some of his later clarifying points. If you go back to the 3.x epic level handbook there is about 30 pages devoted to a multipart ritual subsystem for accomplishing just about anything

Spoiler: Developing your own epic spell

DEVELOPING YOUR OWNEPIC SPELL
An epic spell is developed from smaller pieces called
seeds and connecting pieces called factors. Every epic
seed has a base Spellcraft DC, and every factor has a Spell-
craft DC adjustment. When a desired spell is developed,
the spellcaster spends resources and time to assemble the
pieces that make up the epic spell. The base Spellcraft
DCs of each seed are added together; then the DC adjust-
ments of the factors are added to that total. The sum
equals the final Spellcraft DC for the epic spell.
The final Spellcraft DC is the most significant gauge of
the epic spell’s power. A spellcaster attempts to cast an
epic spell by making a Spellcraft check against the epic
spell’s Spellcraft DC. Thus, a spellcaster knows immedi-
ately, based on her own Spellcraft bonus, what epic spells
are within her capability to cast, which are risky, and
which are beyond her. Epic casters don’t commit time
and money to develop epic spells until they are powerful
enough to cast them.
An epic spell developed by an arcane spellcaster is
arcane, and an epic spell developed by a divine spellcaster
is divine. A character who can cast both divine and
arcane epic spells chooses whether a particular spell he
develops will be arcane or divine. If that same caster uses
the heal or life seed in an epic spell, that spell is always
considered divine.
All the epic spells described earlier in this chapter can
be developed independently by a character who spends
the necessary time, money, and experience points. Alter-
natively, you can use those spells as a starting point when
you create customized versions of the spells. For exam-
pile, if you want a version of vengeful gaze of god that deals
less backlash damage, you are free to develop it.

Unfortunately it's a few editions out of date & was pretty much designed for folks like Eleminster at the time. While that might put some of it on the level with low level 2014 5e power scaling it had the downside of never really getting any lower level seeds & factors making it hard to use without a lot of back & forth tuning a seesaw between intended goal & within power budget but still possible to cast (spellcraft checks well over 100☆ were not uncommon) within the time resource & sacrifice limits that were still possible to swing before really even getting into it

☆That one hundred is not a typo