The Hon’ble Supreme Court in Appaiya v. Andimuthu, 2023 SCC OnLine SC 1183 summarized the principles governing “substantial question of law” in the following words:
“12. The phrase “substantial question of law”, as occurring in the amended Section 100 is not defined in the Code. The word substantial, as qualifying “question of law”, means — of having substance, essential, real, of sound worth, important or considerable. It is to be understood as something in contradistinction with — technical, of no substance or consequence, or academic merely. However, it is clear that the legislature has chosen not to qualify the scope of “substantial question of law” by suffixing the words “of general importance” as has been done in many other provisions such as Section 109 of the Code or Article 133(1)(a) of the Constitution. The substantial question of law on which a second appeal shall be heard need not necessarily be a substantial question of law of general importance. In Guran Ditta v. T. Ram Ditta [AIR 1928 PC 172 : 55 IA 235] , the phrase “substantial question of law” as it was employed in the last clause of the then existing Section 110 CPC (since omitted by the Amendment Act, 1973) came up for consideration and their Lordships held that it did not mean a substantial question of general importance but a substantial question of law which was involved in the case as between the parties. In Sir Chunilal V. Mehta & Sons Ltd. v. Century Spg. and Mfg. Co. Ltd. [1962 Supp (3) SCR 549] the Constitution Bench expressed agreement with the following view taken by a Full Bench of the Madras High Court in Rimmalapudi Subba Rao v. Noony Veeraju AIR 1951 Mad 969] : “[W]hen a question of law is fairly arguable, where there is room for difference of opinion on it or where the Court thought it necessary to deal with that question at some length and discuss alternative views, then the question would be a substantial question of law. On the other hand, if the question was practically covered by the decision of the highest court or if the general principles to be applied in determining the question are well settled and the only question was of applying those principles to the particular facts of the case it would not be a substantial question of law.” and laid down the following test as proper test, for determining whether a question of law raised in the case is substantial: “The proper test for determining whether a question of law raised in the case is substantial would, in our opinion, be whether it is of general public importance or whether it directly and substantially affects the rights of the parties and if so whether it is either an open question in the sense that it is not finally settled by this Court or by the Privy Council or by the Federal Court or is not free from difficulty or calls for discussion of alternative views. If the question is settled by the highest court or the general principles to be applied in determining the question are well settled and there is a mere question of applying those principles or that the plea raised is palpably absurd the question would not be a substantial question of law.
13. In Dy. Commr., Hardoi v. Rama Krishna Narain [AIR 1953 SC 521] also it was held that a question of law of importance to the parties was a substantial question of law entitling the appellant to a certificate under (the then) Section 110 of the Code.
14. A point of law which admits of no two opinions may be a proposition of law but cannot be a substantial question of law. To be “substantial” a question of law must be debatable, not previously settled by law of the land or a binding precedent, and must have a material bearing on the decision of the case, if answered either way, insofar as the rights of the parties before it are concerned. To be a question of law “involving in the case” there must be first a foundation for it laid in the pleadings and the question should emerge from the sustainable findings of fact arrived at by court of facts and it must be necessary to decide that question of law for a just and proper decision of the case. An entirely new point raised for the first time before the High Court is not a question involved in the case unless it goes to the root of the matter. It will, therefore, depend on the facts and circumstance of each case whether a question of law is a substantial one and involved in the case, or not; the paramount overall consideration being the need for striking a judicious balance between the indispensable obligation to do justice at all stages and impelling necessity of avoiding prolongation in the life of any lis.”