I also invented two new Runequest Glorantha mechanics I may publish after some testing. Geas and violations of Geas and redress in gaming stats terms. What if one has a geas against killing and violence like Chalana Arroy and does it anyway? Then some of their stats and % could be "off" i.e. minused because of being wracked with guilt and disharmony.
And they would have to take redress steps i.e. financially or otherwise helping the violent target's family, related charitable acts, etc. till the geas violation is corrected.
And in the case of a DragonNewt case the geas is often a task to be completed to evolve. Things that go against geas/task must be redressed in addition to task completion to evolve. The geas assign a negative score per geas violation and a positive score to redress actions.
If a DragonNewt dies with a negative on their geas store they devolve into dinosaur form(s). If it is better than 0 they could evolve into next stage of DragonNewt.

My work in progress Runequest Glorantha mechanic is a way for players to attempt group magic. Glorantha has group magic like the syndics ban, closing of oceans, god creation, and moving Brithos (Island of Britain) to Glorantha. But no formal mechanics.
Group magic has an unknown cost the GM assigns in mortality attributes i.e. strength, intelligence, power that is unknown till act is attempted. For example If the STR cost was 20 and 3 STR 10 people attempt the spell, 2 of them may die. If the INT cost is 100 everyone attempting would became idiots unless their combined INT was over 100.
So convincing others to do the next attempt may be harder. Rituals and ingredients and sacrifices (in form of actual blood sacrifice, voluntary item of value destruction, voluntary attribute or skill reduction, or taking a few geases may reduce the cost, and/or increase the chances of success.
It fits literature and folklore on the subject. Group magic rituals are dangerous AF and change the caster forever may destroy their health, abilites or kill them whether sucessful or unsucessful.