Some of us might think: What the hell is “Tartarology” and what the hell is “Buddhist Tartarology”? Well, it is supposed to be a doctrine concerning hell and punishment in the afterlife. “Buddhist Tartarology” may be defined as the Buddhist conception and perception of hell (naraka: dmyal ba). Those of us who are new to Buddhist ideas might be surprised to learn that there is a concept of hell also in Buddhism. Regardless of whether we like or dislike the idea of hell (naraka: dmyal ba) in Buddhism, it is a fact. All we can try to do is to understand it and explain it as accurately as we can. Some random points regarding Buddhist Tartarology may be made simply as a venue for exploration. First, the conception of hell in Buddhism seems to be connected with the Buddhist concept of cosmology, which is turn is taught within the context of the “Four Noble Truths” or “Four Truths [that are Accessible to the] Noble Ones [only],” namely, in the context of Truth or Reality of Suffering (duḥkhasatya: sdug bsngal gyi bden pa), specifically in the context of the external “receptacle world” (bhājanaloka: snod kyi ’jig rten), so to speak, the world as a “biosphere” (in the broadest sense possible). Thus it is somehow related with the Buddhist soteriology. By the way, the word “biosphere” seems to be quite suitable here because “receptacle world” is conceived of the terranean (sa steng), subterranean (sa ’og), and superterranean (sa bla) world that support and sustain the so-called “world consisting of sentient beings” (sattvaloka: bcud kyi / sems can gyi ’jig rten), that is, so to speak, “world of habitants.” Hell is, from a Buddhist perspective, a part of the “world of habitats” and a special “biosphere.” Second, hell-realm or sphere of hell is seen as one of the five or six possible destinations in Buddhism. It is the lowest realm among the three “bad destinies” (durgati: ngan ’gro), the other two being the realms of hungry ghosts (preta: yi dwags) and animals (tiryak: dud ’gro). (a) Unlike, for example, in Christianity, one is not sent to hell as a punishment by God. No one can send one to the hell. One can only go to hell by oneself, or, rather, one lands up in the hell-realm on accounts of the multiple causes and conditions that a person would have brought upon oneself. One cannot thus blame anyone else for one’s hellish existence. (b) For most persons, going to hell is not an option or choice. If causes and conditions for one’s hellish existence are absent, incomplete, or not ripe, one cannot go to hell even if one wishes. If causes and conditions for one’s hellish existence have been exhausted, one cannot stay in the hell-ream a minute longer, even if one wishes to stay. Hellish existence may appear long but it is never permanent. Highly realized beings such as buddhas and certain bodhisattvas may willingly go to hell to help hellish beings. They have a choice; not those who are under the sway of their karmic and kleśaic forces. Third, one’s hellish existence is one’s karmic consequence (or self-regulating karmic retribution) and as such one must have accumulated the right karmic deeds by means of the right kind of intellectual-emotional defilements (kleśa: nyon mongs pa). Although several intellectual-emotional defilements may be involved in guaranteeing one’s hellish existence, the dominant cause that can guarantee one’s hellish existence is said to be hatred and maliciousness. From a Buddhist perspective, one may hate and be malicious at one’s own risk. No one else is responsible for one’s hatred and maliciousness and the ensuing karmic consequences. So those of us who wish to be born in the hell can be extremely hateful and malicious. Fourth, Buddhism presupposes various layers or domains of hell corresponding (or proportional) to the intensity and durability of pain and misery. There are said to be eighteen domains of hell (dmyal khams bco brgyad), namely, eight cold hells (grang dmyal brgyad), eight hot hells (tsha dmyal brgyad), auxiliary or peripheral (nye ’khor ba) hells, and micro (nyi tshe ba) hells. The last one is said to be a form of existence in which microorganisms identity with the objects or supports in which they dwell. Fifth, historically, it will be worthwhile to explore how and why Buddhist Tartarology has undergone changes in the intellectual history of Buddhism. Depending on the various doctrinal layers of Buddhism, and depending on the time and place in which Buddhism spread and developed, the conception of hell, too, must have undergone augmentation, modification, and reinterpretation. Two examples may be mentioned here. (a) Śāntideva seems to suggest that hell is nothing but a projection of one’s mind infused with unwholesome deeds. Given the very subjective nature of pain and pleasure, suffering and happiness, one can understand what Śāntideva is trying to suggest. To someone whose mind is pāpa-ridden, everything might appear as hell. But on other hand, some Buddhists might argue that the fact that our miserable destiny is created by our unwholesome resources (pāpa: sdig pa) does not mean that the hellish existence is all in our mind or imagination unless we also posit that other forms of existence, such as animal existence, too, are nothing but mind. The way a Buddhist system conceives hell would thus be influenced by the ontological commitment of that system (e.g. a system’s commitment to realism or idealism). (b) Buddhist Mantric system seems to have introduced a new and deeper level of hell called the vajranaraka (rdo rje’i dmyal ba), that is, so to speak, a biosphere where those who have transgressed cardinal Vajrayānic precepts will be born. Sixth, it may be possible that the conception or rather the depiction of hells in Buddhist sources, systems, and societies had primarily a pedagogical or didactical function. It may have been primarily designed for educating common people about the karmic mechanism. Although Buddhist conception of hell does not presuppose theistic intervention and retribution, Buddhist societies may enact theatrically as if there were a “day of judgment” (metaphorically) where all the “black” and “white” points of a person are counted and accordingly sent to hell headlong.