combat – Rules for intercepting attacks and protecting others

Both the Guardian Ars Magnus and Bodyguard combat module in Dominus Exxet imply that you can intercept an attack directed at other creatures, but I simply cannot find the rules that explain it. I have gone through the Corebook and GM’s Toolkit several times but I have only seen the Push Aside maneuver and covering others with supernatural shields.

Can somebody please explain the rules for intercepting attacks and protecting others, or tell me where is it written?