EDIT - I think.. it is best to have a standard FK hierarchy and multiple Rig Builders, which each exist one bone above the root of each 2 joint IK chain. Eg. the clavicle would have the rig builder and the L_HAND in my example below would sit underneath it. |- CLAVICLE | | -SHOULDER | | | -ELBOW | | | | -HAND | |-runtime rig, containing the 2 bone IK & rig components This hierarchy allows the clavicle to rotate and behave as it should in "standard" rigs. ------------------------------------------------------------------------------------------------------------------ At time of writing, Trump just got beaten by Biden! Good times.... and Unity 2020 has an "in preview" rigging package, which lets us implement simple IK setups. Now there are some third party commercial plugins we could look at - Final IK is probably the top dog at the moment.. Fast IK is free and actually quite good (BUT, for ME, the scripts caused build errors. I