As DM, I am working on a scenario where a lich is bound and gagged but, unexpectedly during combat, the binding loops on one arm are broken and one of the lich's arms gets free.
The adventure is a prisoner escort scenario, but instead of "Hannibal Lecter", the prisoner is a lich.
I am working on how to play out the scenario where relatively lower level PCs are trying to restrain the freed arm of the lich while it is attacking them with its Paralyzing Touch (or possibly casting spells with only somatic components.)
Are there any prior examples in adventures, guidance or rules around how the party would tie up the freed arm of a prisoner?
I looked at grappling but it appears the lich could still use its Paralyzing Touch because a grapple only grabs an opponent and doesn't stop attacks.
Restrained doesn't appear to be the right condition because the creature could still attack.
Incapacitating seems to be the right condition - but given it is only the arm of the creature (the rest of it is already incapacitated) - we are looking for precedent, guidance, or rules.
I believe this question is different from this prior question as we are not asking about all the different ways to invoke the restraining condition, but rather specifically the prior art, guidance or rules around this specific scenario seen with tied prisoners and often portrayed in movies.
Addendum based on questions:
It seems like a common event in prison escort stories that a strong or dangerous prisoner starts to break free and the protagonists must wrestle back control.
Avengers: Infinity War/Endgame example:
Though not strictly a prisoner, a slightly related example is in the recent Avengers movies where scenes showed the heroes wrestling with Thanos' arm to restrain it so they could tear off the glove and Infinity stones.
The lich is bound and gagged because its phylactery hasn't been found and killing it would enable it to reform elsewhere and continue its crimes before its secrets are learned. The plan in the story is to move the lich to a special prison for these types of circumstances. The original high powered escorts were marked and killed by the lich's minions. Now it is left to the lower level PCs to finish the job under great danger and while being pursued by the lich's minions.