Accuracy Avoidance Mitigation Endurance

Accuracy Avoidance Mitigation Endurance

@13033303 via @GobelinNounours

Accuracy, Avoidance, Mitigation, and Endurance are the four terms that Jon Peterson chose to categorize the combat systems in Playing at the World (yes, it's not the first time I write about this book).

It's at this point in the book where Tony Bath's 1966 Medieval rules flow into LGTSA medieval miniature rules, into Chainmail, and then into Dungeons & Dragons.

Here are the four terms and how they manifest in Dungeons & Dragons:

Accuracy is a good term for the offensive property of which Avoidance is the opposing defensive corollary.

The To Hit roll.

Avoidance systems in wargames are mechanisms in which a unit has a quantified, probabilistic resistance to being hit.

The Armor Class, reducing the chance of a hit.

Mitigation, that is the partial or complete nullification, of damage that would be dealt to a character

The Saving Throws are a mitigation mechanism for damage occurring without an accuracy check for the attacker.

By rejecting the prior atomicity of units, Reiswitz inaugurated a tradition of Endurance in wargaming, systems wherein a unit can sustain quantitative damage — which Reiswitz referred to by the English word "points" — without being destroyed

The Hit Points. Contrast that with Chess, the ur wargame where unit status is binary.

A quick side note: as a francophone player, when I was a kid, we said "Points de Vie" (Life Points) in my neck of the woods, we didn't say "Points de Coup" (Hit Points) and that was a bit unfortunate because it was colouring our perception of the concept.


As these concepts are critical for understanding the design of Dungeons & Dragons, note that mitigation and endurance systems are completely orthogonal to how hits are determined. Mitigation takes place after an accuracy or avoidance check (if any, as in the spellcasting case in Dungeons & Dragons there is none) has already occurred, only when the resulting damage is absorbed in whole or in part.

Failing to hit a target altogether (typically because of the poor outcome fo a "to-hit" roll) results in a similar lack of damage, but that must be considered separately as avoidance from the perspective of system design.

Confusingly, mitigation and endurance in different systems might be intended to model the same property of the "real" world — the rationalization for withstanding damage is, however, also separable from the manner in which its behavior is systematized in a game. Furthermore, when they do model different properties, endurance and mitigation are not mutually exclusive. While they serve similar purposes (forestalling the loss of units), they are sometimes employed concurrently, or to be more precise, serially.


In 2021, I wrote about First Legends' combat aspect. In that french game, Accuracy is provided by a skill check (club, ace, mace), the adversary may choose to exercise Avoidance and do a Dodge skill check (nullifying a successful hit) or to exercise Mitigation with a Parry skill check (whose success margin reduces the damage points incurred). Finally there is passive Mitigation with the armor absorbing some or all of the remaining damage points. Endurance, finally is provided by Strain Points (Physical * 2 + Mental).

Thus, beyond understanding the design of Dungeon & Dragons, I think these concepts are a useful tool for designing and/or evaluating combat systems. It might even be useful when looking at social combat systems.


And a last quote for Dungeons & Dragons and its level scale:

At higher level, therefore, the system relies increasingly on endurance to guard against precipitous deaths.