Historical Rules · 10 June 2022
Rule 122.1c
Official source text from the 10 June 2022 Rules release
A shield counter on a permanent creates one replacement effect and one prevention effect that protect the permanent. These effects are “If this permanent would be destroyed as the result of an effect, instead remove a shield counter from it” and “If damage would be dealt to this permanent, prevent that damage and remove a shield counter from it.” See rule 614, “Replacement Effects,” and rule 615, “Prevention Effects.”