The Quranic scheme of inheritance assigns fixed fractional shares to a closed class of nine (Hanafi: twelve) sharers — half, two-thirds, one-third, one-sixth, one-eighth, one-fourth — and then leaves the residue, if any, to the agnatic male heirs called residuaries. When the arithmetic works out neatly, the sharers take their fractions, the residuaries take what is left, and the estate distributes to unity. But the Quranic fractions were never designed to be added together in every conceivable family combination. There are family patterns in which the sum of the prescribed shares exceeds unity, and other patterns in which the sum falls short of unity with no residuary in sight. The two classical correctives that resolve these arithmetical anomalies are the doctrine of Aul (Increase) and the doctrine of Radd (Return), and the leaders of every major exam set at least one sum that turns on them.
Aul and Radd are not statutory creations. They are juristic devices developed in the early Islamic centuries — Aul attributed to the second Caliph Umar after consultation with the Companions, Radd traced to Ibn Abbas — and absorbed into Indian courts through Muslim Law as a whole, which is applied to questions of intestate succession by virtue of Section 2 of the Muslim Personal Law (Shariat) Application Act, 1937. Both doctrines proceed entirely outside the Hindu Succession Act, the Indian Succession Act, and the Transfer of Property Act, 1882. They are pure Quranic-arithmetic correctives, and the candidate must master them as such.
Statutory and shariah anchor
The Indian statutory peg is short. Section 2 of the Muslim Personal Law (Shariat) Application Act, 1937 directs that in matters of intestate succession, where the parties are Muslims, the rule of decision shall be the Muslim personal law (the Shariat). The statute supplies the choice-of-law rule; the substantive content is shariah. The Quranic source for the fixed shares is principally Surah Al-Nisa, verses 11, 12 and 176 — the verses that prescribe the share of children, parents, spouses, and collaterals. Hadith narrations from the Sahih collections supplement the Quranic shares for the residuaries. The classical jurisprudential authorities most often consulted are the Sirajiyyah of Sirajuddin al-Sajawandi, with its standard commentary the Sharifiyyah, and Baillie's Digest of Mohammedan Law for the Hanafi school; the Sharai-ul-Islam is the leading authority for the Shia (Ithna Ashari) treatment.
It is important at the threshold to flag the school distinction. The Hanafi school — which governs the overwhelming majority of Indian Muslims — accepts both Aul and Radd. The Ithna Ashari Shia school accepts Radd in an altered form but rejects Aul outright as a matter of doctrine. That divergence is examined under the heading on Shia divergence below.
The arithmetic problem the doctrines solve
To understand Aul and Radd you have to start with the closed character of the Quranic share-list. Under Sunni (Hanafi) inheritance, the twelve sharers are: husband, wife, father, true grandfather, mother, true grandmother, daughter, son's daughter, full sister, consanguine sister, uterine brother and uterine sister. Each is assigned a share — for instance, the husband takes one-half if there is no lineal descendant and one-fourth if there is; the wife takes one-fourth or one-eighth on the same condition; the father takes one-sixth as a sharer when there is a lineal descendant; the daughter takes one-half alone or two-thirds together; full sisters take one-half alone or two-thirds collectively, and so on.
Most family patterns leave a residue after the sharers' shares are allotted, and the residuaries — the agnates beginning with the son and stretching through the brother, the paternal uncle, and their respective lines — absorb that residue. The arithmetic is simple, the answer is unique. The trouble starts in two narrow but recurring patterns:
- Excess. The combined Quranic shares of the surviving sharers, when reduced to a common denominator, sum to more than one. There is no surplus to allot — there is a deficit. The estate is over-allocated.
- Shortfall. The combined Quranic shares of the surviving sharers sum to less than one, and there is no residuary alive to soak up the residue. There is no claimant for the surplus, and the surplus must somewhere find a destination.
Aul addresses the first problem. Radd addresses the second. Each is essentially a method of fitting the closed Quranic shares to the realities of an open universe of family configurations.
Aul — the doctrine of Increase
The doctrine of Aul applies when the sum of the Quranic fractional shares allotted to the surviving sharers exceeds unity. The mechanism is mathematically straightforward: reduce all shares to a common denominator, take the sum of the numerators, and substitute that sum for the denominator. The new shares preserve the ratios between the sharers but proportionally reduce each share so that the total equals unity. The doctrine is called "Increase" because the denominator is increased from the original common denominator (six, twelve or twenty-four, depending on the case) to the larger sum of the numerators (seven, eight, nine, ten, thirteen, fifteen, seventeen or twenty-seven, depending on the case).
The classical worked example: a Hanafi Muslim dies leaving a husband and two full sisters. The husband, with no lineal descendant, takes one-half. Two full sisters take two-thirds collectively. Reduce to a common denominator of six. Husband: three-sixths. Sisters: four-sixths. Sum of numerators: seven. The original denominator six is increased to seven. Husband now takes three-sevenths; the two full sisters between them take four-sevenths. The estate distributes to unity, and each sharer's share has been proportionally diminished without altering the ratio between them.
The arithmetic accommodation is mechanical, but the doctrinal point is interesting. Aul does not pick favourites. It does not, for instance, exempt the husband or the parents from proportional reduction. Every sharer suffers a pro-rata cut. Indian decisions on partition apply this proportional diminution rule without controversy.
When Aul cannot arise
The candidate should know the negative case. Aul cannot arise where there is a son or a son's son or, in the absence of the father, a true grandfather among the surviving heirs, because in those configurations the rules of Sunni inheritance are so calibrated that some residue is invariably left for these residuaries. The five most-favoured "primary heirs" — child, father, mother, husband and wife — are never excluded; their substitutes (child of son, true grandfather, true grandmother) step in when the primary heir is absent. Aul is therefore confined to the patterns where the surviving sharers are some combination of (a) spouses, (b) parents, (c) daughters or son's daughters, and/or (d) collateral sisters and uterine siblings — and where the daughters' or sisters' classes are present in numbers that drive the fractions over unity.
Aul — additional patterns
Once the candidate understands the basic 7/6 → 7/7 movement, the higher-order Aul cases fall out naturally. The classical denominators that emerge are 7, 8, 9, 10, 13, 15, 17 and 27. Some illustrative patterns:
- Husband (1/2 = 3/6) + two full sisters (2/3 = 4/6) + uterine sister (1/6) = 8/6, increased to denominator 8: husband 3/8, sisters 4/8, uterine sister 1/8.
- Husband (1/4 = 3/12) + two daughters (2/3 = 8/12) + father (1/6 = 2/12) + mother (1/6 = 2/12) = 15/12, increased to denominator 15: husband 3/15, daughters 8/15 (4/15 each), father 2/15, mother 2/15.
- The most-cited stress case under Hanafi rules — daughter (1/2 = 6/12) + son's daughter (1/6 = 2/12) + husband (1/4 = 3/12) + mother (1/6 = 2/12) = 13/12, increased to denominator 13: daughter 6/13, son's daughter 2/13, husband 3/13, mother 2/13. The full sister, who could only have inherited as a residuary with the daughter and son's daughter, is in this pattern entirely excluded because the case is one of "Increase" with no residue at all.
Note in the third pattern that Aul has the secondary doctrinal effect of excluding a relative who would otherwise have inherited as a residuary-with-others. Once the sharers' fractions absorb the entire estate, no residue remains for the would-be residuary, and exclusion follows by simple arithmetic.
School, sub-school, sapinda — get the distinctions tested.
Topic-tagged MCQs from previous-year papers and original mocks — calibrated to actual exam difficulty.
Take the personal-laws mock →Radd — the doctrine of Return
The doctrine of Radd applies in the converse situation: the Quranic shares of the surviving sharers, when summed, are less than unity, and there is no residuary alive to absorb the surplus. The shariah will not permit the residue to escheat to the State so long as any blood-sharer is alive. The surplus therefore reverts — "returns" — to the sharers in proportion to their existing Quranic shares. The mechanism of Radd is the mirror-image of Aul: reduce shares to a common denominator, then decrease the denominator to the sum of the numerators. The new shares preserve the ratios but proportionally enlarge each share so that the total equals unity.
A classical worked example: the deceased leaves a mother (Quranic share 1/6) and a son's daughter (Quranic share 1/2) and no residuary. Reduce to common denominator six: mother 1/6, son's daughter 3/6, total 4/6. The total falls short of unity by 2/6. Apply Radd: decrease denominator from 6 to 4. The mother now takes 1/4; the son's daughter takes 3/4. The ratios between the sharers (1:3) are preserved; each share is proportionally enlarged.
The husband and wife exception to Radd
The classical Hanafi rule is firm and important. Neither the husband nor the wife is entitled to share in the Return so long as any other heir — sharer or distant kinsman — survives. The reason runs deep into the structure of the Quranic shares: the husband and wife inherit by reason of marriage (an affinity link), not by reason of blood (consanguinity). The Return doctrine is grounded on blood-relationship, and the spousal share — once paid as a Quranic fraction — is treated as the spouse's full entitlement.
Worked example: the deceased leaves a husband and a mother. The husband takes one-half as sharer. The mother, in this configuration (no lineal descendant, no two or more siblings), takes one-third as sharer. The total of one-half plus one-third is five-sixths; the surplus is one-sixth. The husband does not share in the Return. The mother takes the surplus one-sixth by Return, raising her share from one-third to one-half (one-third as sharer plus one-sixth by Return). Husband: one-half. Mother: one-half.
The exception to the exception: where the only heir is the spouse — i.e., the deceased leaves a sole-surviving widow or widower with no sharer, no residuary, and no distant kinsman — the surplus does not escheat to the Crown but goes to the sole spouse by Return. The leading Indian decisions sustaining this proposition were in Mahomed Arshad v. Sajida Banoo and Bafatun v. Bilaiti Khanum; both refused to allow the State to take by escheat where the widow alone survived. The widow takes one-quarter as sharer and the remaining three-quarters by Return.
Radd patterns to memorise
- Sole widow. Widow takes 1/4 as sharer + 3/4 by Return = whole estate.
- Sole daughter. Daughter takes 1/2 as sharer + 1/2 by Return = whole estate.
- Husband + daughter. Husband 1/4 (no Return); daughter 3/4 (1/2 as sharer + 1/4 by Return).
- Wife + son's daughter. Wife 1/8 (no Return); son's daughter 7/8 (1/2 as sharer + 3/8 by Return).
- Mother + father's mother + two daughters. Original: mother 1/6, father's mother excluded (mother is alive), two daughters 2/3. Where the mother is replaced by, say, paternal grandmother only: father's mother 1/6 (= 1/6) + two daughters 2/3 (= 4/6) = 5/6, decreased from 6 to 5: father's mother 1/5, two daughters 4/5 (each 2/5).
The candidate should commit the husband-wife exception to memory because at least one mid-difficulty MCQ on Radd in any State judiciary paper will turn on it. The widow-only escheat exception (the Bafatun line of cases) is the favoured PYQ in the personal-law Mains of several state services, including those that test landmark Muslim law decisions.
Shia divergence — the rejection of Aul
The Ithna Ashari Shia school decisively breaks from the Hanafi position on Aul. Shia jurisprudence rejects Aul on the doctrinal ground that the Quranic shares cannot be diminished by judicial act, and that any apparent excess must be absorbed at the expense of certain disfavoured heirs — historically, daughters and sisters were not asked to suffer reduction; the burden of the deficit fell on "the relations of the lower order" or, in Shia analysis, on heirs whose share was treated as the residual rather than the prescribed entitlement. The practical Shia method is therefore to reallocate the deficit to a particular class rather than to spread it pro-rata.
On Radd, the Shia school accepts the doctrine of Return in an altered form, with one important divergence on the wife. In Shia analysis, where the only heir is a wife, the older view is that she takes only her Koranic 1/4 and the residue 3/4 escheats to the Imam — and, in present-day India, to the Government as the Imam's representative. Ameer Ali argued that since there is no machinery to take the Imam's share, the surplus should pass to the wife by Return; the Oudh Court in Abdul Hamid Khan v. Peare Mirza followed Ameer Ali's view. The position is unsettled and a likely PYQ trap. For the husband under Shia law, the husband as sole heir takes the whole estate (one-half as sharer plus one-half by Return).
The deeper reason for the Shia rejection of Aul lies in the Shia–Sunni divergence on the structure of inheritance itself. Shia law admits no separate class of "distant kindred" and divides heirs into three classes by consanguinity, with the principle of representation applied throughout. Aul was, on the Shia view, a Caliph Umar–era doctrinal mistake imposed on a system that does not require it.
Interaction with other estate-law concepts
Two interactions are worth noting for the exam.
First, Aul and Radd both operate after deduction of funeral expenses, debts, and bequests up to the one-third bequeathable maximum. The arithmetic of Aul and Radd is performed on the net estate left for distribution, never on the gross. The candidate should always state — even on a one-mark MCQ — that the estate to which the doctrines apply is the residue after debts and bequests, never the bequeathable third.
Second, Aul and Radd are doctrines of intestate succession only. Where the deceased has left a valid wasiyat (will) within the one-third limit, that will is honoured first. Aul and Radd then apply only to the remaining two-thirds of the estate that pass by intestate succession, subject to the consent of heirs to any bequest exceeding the one-third or to any heir.
Doctrinal critiques and reformist responses
Later reformist commentators have observed that Aul produces a result identical to a pro-rata abatement, and that the Shia rejection of Aul produces results that are doctrinally tidier but socially regressive — typically reducing the daughter's or sister's share to make the spouses' fractions whole. The Hanafi acceptance of Aul, by spreading the deficit pro-rata across all sharers, treats every Quranic sharer as equally entitled to whatever fraction the arithmetic permits. Whatever the merits of the academic debate, the candidate's task is descriptive, not normative: state both rules accurately, identify the school, and apply.
Indian case law and exam-angle distinctions
Indian courts have applied Aul and Radd in partition and succession suits without doctrinal innovation. The judicial role is largely arithmetic: identify the surviving heirs, classify them as sharers, residuaries, or distant kindred, allot the Quranic shares, run the Aul or Radd calculation as required, and decree partition. Where the estate is small or undivided, courts proceed by per-stirpes notional division (in Shia cases) or per-capita actual division (in Sunni cases) following the doctrines applied. The principal Indian authorities sustaining Radd against Crown escheat — Mahomed Arshad, Bafatun, and Mir Ilsub v. Isab — are all 19th-century-into-early-20th-century decisions still followed today. The line is good law because escheat to the Crown was always treated as a residual jurisdiction triggered only by total failure of heirs.
One trap to avoid: Aul and Radd never apply to a transfer for consideration. A sale, mortgage, or hiba-bil-iwaz is governed by the rules of those transactions, not by the rules of intestate succession. The test is always whether the property passes by operation of law as inheritance.
Reading list — what to commit to memory
For the State judiciary candidate, the working knowledge must comprise: (a) the Quranic share-list with its conditional variants; (b) the seven principal Aul denominators (7, 8, 9, 10, 13, 15, 17, 27) and a worked example for each; (c) the Radd mechanism with the husband-wife exception and the Bafatun escheat-defeating rule; (d) the Shia rejection of Aul and the Shia treatment of the sole widow under the older view versus the Ameer Ali / Oudh view; (e) the placement of Aul and Radd within the overall scheme of intestate succession after debts, expenses, and bequests; (f) the practical contrast with the doctrine of Shia inheritance classification and with the gendered residuary rules of Hanafi succession; and (g) at least two leading Indian decisions on each doctrine.
The doctrines reward arithmetical fluency. They are perfect MCQ material because they admit of unique numerical answers, and they are perfect Mains material because they require the candidate to state the rule, classify the heirs, apply the doctrine, and produce the partition shares with reasoning. The candidate who can do all of this in three minutes for the Sunni case and five for the Shia case has substantially de-risked the personal-laws section of the paper. A practical study tip: prepare a one-page reference card listing each Aul denominator beside its triggering family pattern, and a parallel page for the Radd patterns showing the husband-wife exception in red ink. Drilling those two cards for ten minutes before any judiciary paper on personal law tends to convert these sums into instinctive recognition rather than slow calculation, and the time saved usually rescues at least one borderline question elsewhere in the paper.
Frequently asked questions
Why is the doctrine called Aul or Increase when the shares actually decrease?
The label refers to what happens to the denominator of the fractions, not to what happens to the share each heir takes. When the sum of Quranic shares exceeds unity, the surviving heirs' shares are reduced to a common denominator and the denominator is then increased so as to equal the sum of the numerators. By increasing the denominator from, say, six to seven, the total of the shares is brought down to one. The doctrine is called Increase because the denominator is increased; the consequence is that each heir's share is proportionally diminished. The terminology preserves the original Quranic numerators while saving the arithmetic of partition.
Are the husband and wife entitled to take by Return (Radd)?
As a general rule, no. So long as any other heir survives — sharer, residuary or distant kinsman — the husband and wife are excluded from sharing in the surplus by Return. Their Quranic share is treated as their full entitlement. The exception applies only where the husband or wife is the sole surviving heir and there is no other claimant. In that narrow case the surplus does not escheat to the Crown but passes to the sole spouse by Return. The Indian decisions in Mahomed Arshad v. Sajida Banoo and Bafatun v. Bilaiti Khanum sustained the widow's right against escheat. The rule is firm under Hanafi law; under Shia law the position of the sole widow is unsettled.
How is the Shia school different from the Sunni school on Aul and Radd?
The Ithna Ashari Shia school rejects Aul outright. Where the Quranic shares exceed unity in a Shia case, the deficit is absorbed by reducing only the share of certain disfavoured heirs — typically those whose entitlement is treated as residual — rather than by a pro-rata abatement across all sharers. The Shia school accepts Radd in an altered form. The principal Shia divergence on Radd concerns the sole widow: the older view (Sharaya-ul-Islam) is that she takes only her Quranic 1/4 and the residue escheats to the Imam, with Ameer Ali and the Oudh Court in Abdul Hamid Khan v. Peare Mirza taking the contrary view that the surplus passes to the widow.
Can Aul and Radd both arise in the same case?
No. The two doctrines address opposite arithmetical anomalies. Aul applies where the sum of Quranic shares exceeds unity; Radd applies where the sum falls short of unity and there is no residuary. A given factual matrix produces either one or the other or neither, never both. Where the sum equals unity exactly — the most common outcome — neither doctrine applies and the estate distributes on the bare Quranic shares. Where a residuary survives and the sum of sharers' shares is less than unity, the residue passes to the residuary by the ordinary rule, again without Radd. The candidate should test for Aul, then for residuary, then for Radd in that order.
When is Aul not possible at all?
Aul cannot arise where there is a son, a son's son, or — in the absence of the father — a true grandfather among the surviving heirs. The reason is that these residuaries always take some residue under the Hanafi share scheme, and the rules of succession are calibrated to ensure that some residue invariably remains when any of them is alive. Aul is therefore confined to family patterns made up of spouses, parents, daughters or son's daughters, and collateral siblings, where the daughters' or sisters' classes are present in numbers that drive the cumulative fractions over unity. The candidate's first arithmetical move on any partition problem is to look for a son or true grandfather; if either is present, Aul is impossible.