Ritual magic has several aspects that make it very useful: It can draw on natural energy and so not require the caster to use as much of their own internal energy, It can be cast by multiple people allowing larger amounts of energy to be used, and since it can be performed by a variable number of people they can split up the load of a spell among themselves. However it’s not all roses, as Rituals require more time with few being usable during combat and you need multiple trained spellcasters to operate most Rituals. The simplest Rituals don’t require lots of energy, but are so complex that to use takes a considerable amount of time. The most powerful rituals are both complex and take massive amounts of energy, but can have amazing effects. While not much is known about Elven Ritual Magic, the wards they build over their forest are incredibly powerful and likely the result of exceedingly powerful Rituals.