a proprio rischio e pericolo

Italian

Literally, “at one's risk and danger”. Compare French à ses risques et périls.

(idiomatic) at one's own risk, at one's own peril
- 2020, Barack Obama, chapter 11, in Chicca Galli, Paolo Lucca, Giuseppe Maugeri, transl., Una terra promessa [A Promised Land], Garzanti Libri:
  Potevi certo decidere di alzare comunque la voce per una questione di coscienza, ma dovevi sapere che ci sarebbe stato un prezzo da pagare, che i neri potevano praticare la politica di difesa degli interessi particolari degli agricoltori, degli appassionati di armi o di qualsiasi altro gruppo etnico solo a loro rischio e pericolo.
  You might decide to speak up anyway, as a matter of conscience, but you understood there'd be a price—that Blacks could practice the standard special-interest politics of farmers, gun enthusiasts, or other ethnic groups only at their own peril.
  (literally, “You could certainly decide to raise your voice anyways as a matter of conscience, but you had to know that there would be a price to pay, that blacks could practice the defensive, special-interest politics of farmers, gun enthusiasts or whichever other ethnic group only at their own peril.”)