How are rights restored to their owners in light of the changing value of currency: should it be according to its value at the time of the debt/theft, or its current value?

If the debt consists of tangible assets that have intrinsic value, such as gold and silver, then it is obligatory to return the equivalent in kind, regardless of any change in value. This is the view of the majority of scholars.

However, if the debt is in paper currency: 1. If the decrease in the currency's value is slight (not reaching one-third of the debt's value), then it is obligatory to return the same number of units of currency, without increase or decrease. 2. If the change in currency value is significant (reaching one-third or more), contemporary scholars have differed. The more accurate opinion is that it is obligatory to return the value or for the two parties to reach a settlement. The value should be estimated based on the price of gold at the time the debt was incurred or based on the purchasing power of the currency at that time. Payment must be made in a different currency to avoid usury (riba).

An usurper and a thief must return the currency according to its value on the day of usurpation or theft, or guarantee the decrease in value of the stolen tangible items.

As for other debts arising from mutual agreement, if the change is significant, it is obligatory for the two parties to reconcile by distributing the loss between them.