Market Linked Debentures are instruments that do not have a fixed pay-off. Instead, their payoff depends upon the performance of another index like Nifty 50 or security like the 10-year G-sec. Upon maturity, a payoff or return payable is accrued along with the initial principal payment. This return payable is dependent on the movement of the underlying index or security that the MLD follows, as initially defined in the terms.