IANAL, but NO. Duress only applies if they bullied you to sign. On the other hand, other laws may invalidate that clause. See a lawyer. Also, before you sign

IANAL, but NO. Duress only applies if they bullied you to sign. On the other hand, other laws may invalidate that clause. See a lawyer. Also, before you sign any contract (in Australia, if the contract is written by the other party) you can modify it by just "asking for clarification". If you ask the manager what the fine print means, and they say "nothing", it strikes out the fine print (in theory, but in practice you need to convince the court that this happened). You might want to have some written record, preferable signed by the manager, though.