The base contract
The capital provider (rab al maal) contributes funds. The labor provider (mudarib) operates the venture. Profit is shared in a ratio agreed at signing (any negotiated split is permissible). Loss is borne by rab al maal alone, unless the mudarib was negligent or violated terms.
The mudarib bears the loss of effort, not capital. This asymmetric loss-sharing is the structural feature that distinguishes Mudarabah from Musharakah.
Where Mudarabah shows up
Halal savings accounts: the bank is the mudarib, depositors are rab al maal. The bank invests deposits in permissible activities and shares profit with depositors. Returns are not guaranteed and not interest; they reflect the bank's actual investment results.
Islamic investment funds: the fund manager is the mudarib, investors are rab al maal. The Mudarabah agreement governs profit allocation between manager and investors.
Investment opportunities (the third pillar on halalrates): some sponsor-led deals are structured as Mudarabah, with the sponsor as mudarib and investors as rab al maal. Mufti review verifies the loss treatment matches the structure.
The two-tier structure
Many halal banks operate a two-tier Mudarabah: depositors are rab al maal to the bank (which is mudarib for the deposit), and the bank is rab al maal to entrepreneurs it finances (who are mudarib for the financing). Each tier carries its own risk-sharing rule.