To what extent is an accused person obligated to take an oath when accused of committing an act such as theft or false reporting without evidence, and what is the legitimate Shariah rule that determines which accusations necessitate an oath?

The basis for a claim is the saying of the Prophet, peace and blessings be upon him: "The burden of proof is on the claimant, and the oath is on the defendant." For a claim to be valid, certain conditions must be met: it must be known and detailed, binding, the claimant must identify their opponent, the claimant must be an adult of sound mind, the claim must be against a responsible individual (mukallaf), the claim must not contradict itself, the claim must be verifiable, and it must not contravene custom or common practice. A claim can be heard between two disputants even if there was no prior interaction or transaction between them.