Arguably the most important difference between tabletop role-playing games and other forms of interactive fiction, like LARPing and community theater, is the reliance on random chance to determine the results of player actions. Of the many ways of mechanically generating luck, dice have several advantages: they are cheap and ubiquitous, historically and culturally recognizeable, and accessible to nearly everyone. For our purposes as game designers, however, dice are most valuable not for these their inherent qualities, but for how they can be manipulated and developed through game systems and narrative.

HALFLIGHT uses a conventional pair of six-sided die for all adjudications, hereby referred to as 2d6. Whenever a roll is called for, the Player will roll both dice together, and hope for a resulting sum of 8 – 10, a “success.” Anything below 8 is considered a “failure,” while anything above 10 is denoted as “excess,” with the combined traits of both a success and a failure (all rolls above 12 are considered as 12 for this purpose). Two subsystems, Grief and Boons and Banes, alter this further by allowing Players and the Adversary to add or subtract from the results of the roll before adjudication. This system was one that I have only seen once before (with different terminology), in the game Libreté by Vivi Fée, whose English edition I published in 2020. Why this system was chosen for HALFLIGHT, and how its idiosyncracies sublimely suit the narrative and mechanical structure of the game, is the purpose of this essay.

But first, a brief history. While I am a strong supporter of the polyhedral dice set (minus the d10, which as a non-Platonic solid is an abomination that should be excised from the role-playing canon), it is relatively juvenile in the long history of games. The six-sided die predates the written human record, and its use as a tool for gambling and auspicion crosses nearly every historical and cultural boundary. In fact, its design often reflected the predominant cultural and religious views of the time and place: Roman dice, for example, were notoriously poor reflectors of random chance, often lopsided and weighted either “high” or “low” through a particular distribution of faces. This was not seen as a problem: rolls were predetermined by the will of the fates or the intervention of gods, and the dice were merely a conduit for the message, not the message itself.

Dice in Europe became fairly standardized after the Renaissance, taking on the form and number distribution that we recognize today. While fairly popular for gaming within the Medieval period, it is around this time that their use as a function of courting random chance became codified. By the 18th century, the time period that most closely resembles the world of HALFLIGHT, several parlor games utilizing 2d6 had developed and were exceedingly popular among the European upper class. Hazard, a game first attested to in Geoffrey Chaucer’s Canterbury Tales, utlizes the 2d6’s center-weighted probability by having the caster first designate a number between 5 and 9, and then taking turns with other people in an attempt to roll it or an accompanying “partner” number, usually either 11 or 12. This was a game of complete and utter chance, with no possibility (excepting legerdemain) for the caster to gain an advantage over their opponents. As such, its inclusion here is as an interesting novelty, and an example of the 2d6’s gaming pedigree.

Another game from this time period, while perhaps less interesting to ginroom gamblers, is far more appealing for the purposes of art and storytelling. The Musikalisches Würfelspiel were a loose assemblage of systems for the purpose of randomly generating musical compositions. These games were designed in a way very similar to the modern notion of a randomly-generated dungeon: several tables of possible arrangements were presented, each corresponding to a particular result on a 2d6 dice roll, and after rolling on each table the resulting composition could be played in its entirety and (hopefully) emerge as something other than pure cacophany. While there is still no evidence of anything but random chance in play, the chance here is used to create a shared experience with other players. Each result builds upon the results preceeding it and is incorporated into the melody, a single small dice roll becoming part of something greater when placed alongside many others.

I admit to a bit of HARKing (Hypothesizing After Results are Known) in relating HALFLIGHT to the above games, as I had already made the decision to adopt Vivi Fée’s dice mechanics before I began researching the history of dice games in the 18th century. In fact, my primary motivator in choosing this system above all others was purely mechanical: I simply believe that the probability curve of a 2d6 roll. augmented by voluntary addition and subtraction, produces a uniquely beautiful set of outcomes. Allow me to explain, in mathematical terms as simple as my untrained mind can produce.

An unadulterated roll of 2d6 produces an outcome of 2 – 12, with an average roll of 7. As mentioned before, HALFLIGHT deems any result below 8 to be a failure, which means that such a roll will fail more often than it will succeed. This would be extraordinarily unsatisfying to many players, which is why this system is bolstered by two subsystems that each tweak the odds in different ways.

+ represents a Boon, where the Player may add +1 to the roll at their discretion.
− represents a Bane, where the Adversary may subtract −1 from the roll at their discretion.
Boon and Bane resolution probabilities assume the Player will always use a Boon to achieve Success (when possible) and the Adversary will always use a Bane to achieve Failure (when possible).

Grief is a narrative expression of a Player Character’s emotional and mental strain, and can be taken willingly by a Player at any time. While there is no strict upper limit on Grief, many Players will want to keep their reserve under 5, as that is the point where their Character is at risk of succumbing to Frenzy, a debilitating loss of composure that can have devastating consequences on morale and survival. With few exceptions, the way Player Characters divest themselves of Grief is by investing it into their actions: up to three Grief can be used in this way, wagered before the roll is made and added to the result. Narratively, this reflects a Character’s willingness to “let themselves go” and augment their actions with the accumulated stress and anxiety that comes from Dungeon exploration.

An investment of Grief dramatically changes the probability curve. Whereas before the average roll was 7, the average roll of a 2d6+3 is 10: a perfect success! If we collate each of the three broad categories of results, the difference is even starker: whereas the possibility of failure on a 2d6 roll is 58.4%, and success a mere 33.3%, those chances become 16.7% and 41.7%, respectively, on a 2d6+3 roll. Interestingly enough, the possibility of a success doesn’t change very much with how much Grief you invest, as long as you invest some. Investing 2 Grief gives you the best odds at 44.5%, but that is only slightly above the 41.7% you get from investing 1 or 3 Grief. Each is a monumental step above the 33.3% chance you have with no Grief.

+ represents a Boon, where the Player may add +1 to the roll at their discretion.
− represents a Bane, where the Adversary may subtract −1 from the roll at their discretion.
Boon and Bane resolution probabilities assume the Player will always use a Boon to achieve Success (when possible) and the Adversary will always use a Bane to achieve Failure (when possible).

However, there is a possibility that we have not considered: a result of 11+, an excess. Excesses combine the consequences of success and failure: the Character may get what they want, but it’s not without a price. Perhaps they go a bit too far, endangering themselves or others. Perhaps other Characters are shocked or sickened by a particularly ruthless act of violence, or a Character on the verge of a breakdown may reveal their true misgivings about the current mission. Given this narrative, it is suitable that the risk of an excess increases as more Grief is invested. With zero Grief, your chance of excess are a mere 8.4%, significantly less than your odds of either failure or success. However, with 3 Grief your chances of success or excess are perfectly equal; the more of yourself you are willing to give, the more you are able to take.

The second subsystem in play here is called Boons and Banes, two equal-but-opposite forces that can provide a +1 or a -1 to a roll. These were called “positions of strength” or “positions of weakness” in Libreté, and were given whenever the Players and the Adversary agreed that the Player Character making the roll had a particular advantage or disadvantage on the task at hand. This could come from the environment, tactics, equipment, pretty much anything except intent — it was always assumed that a Player Character would want to succeed and apply all of their willpower to doing so.

The important mechanical caveat to Boons and Banes is in how they are applied: a Player whose Player Character has a Boon can choose to take +1 to their roll after the roll is decided, in contrast to Grief which must be invested before a roll. Conversely, Characters with a Bane are at the mercy of the Adversary, who may choose to impose a -1 penalty to the roll after it is adjudicated. This means that a Boon can never be used to avoid or incite excess (if anything, hitting the opponent a little too hard is easier if you’ve got the high ground, and harder if you’re caught on the back foot), but can be used to push a near-failure into success, and vice versa. This makes them a powerful tool in the hands of Players, who can use them in place of Grief to more safely and reliably achieve success.

As I assembled this data, what at first seemed a morass of meaningless numbers coalesced into one of the most diagetically pleasing resolution mechanics I’ve ever seen. Witness how failure and excess are intrinsically tied as more Grief is invested: as one decreases, the other increases in equal measure. Note how excess is solely a factor of Grief, entirely divorced from Boons or Banes. And behind it all is the overwhelming threat of failure: without clever planning and actively engaging with the system, you will always fail more often than you succeed.

HALFLIGHT proclaims itself “Gothic horror role-playing”, with all the narrative elements that entails: tortured protagonists teetering on the precipice of sanity, suffused with grief and the weight of their deeds, struggling to cope with the real and percieved failures of themselves and those around them. It’s a game where struggle is measured in pints; success, in ounces. I’ve always been intrigued by the ways that a game’s mechanics can influence and amplify its setting and tone, and with this system, I think the two are in near-perfect harmony.

¹ Buchanan, Kate. “How Dice Changed in the Middle Ages.” Medievalist. https://www.medievalists.net/2018/02/dice-changed-middle-ages/.
² Hedges, Stephen A. “Dice Music in the Eighteenth Century.” Music & Letters 59, no. 2 (1978): 180–87. http://www.jstor.org/stable/734136.