Rocky Reads for #Wargame…K-Pop? Republic of Korea Navy Damage Model vs. Harpoon V (admiraltytrilogy.com)

Thanks to Rex Brynen at PAXSIMS for pointing out some recent modeling & simulation (and wargame) professional reading. One of the articles is from a South Korean journal and discusses the Republic of Korea (ROK) Navy wargame model for ship damage.

Wargame is a simulated military operation with certain rules, specifications, and procedures, in which soldiers can virtually and indirectly experience the war. The ROK Navy operates the Cheonghae model, a training wargame model for helping commanders and staff master the procedures for conducting the war. It is important for commanders, staff and analysts to know whether a warship can perform its missions and how long it can last during a war. In existing model, the Cheonghae, the probability of kill of a warship is calculated simply considering the number of tonnage without any stochastic elements, and the warship’s mission availability is also determined based on predetermined values. With this model, it is difficult to get a value of the probability of kill that makes sense. In this dissertation, the author has developed a probabilistic model in which the warship vulnerability data of ROK-JMEM can be used. A conceptual model and methodology that can evaluate the mission performance of personnel, equipment, and supplies has been proposed. This can be expanded to a comprehensive assessment of wartime warship loss rates by integrating damage rates for personnel, equipment, and supplies in wartime.

Bong Seok Kim , Bong Wan Choi , Chong Su Kim, “Methodology of battle damage assessment in the naval wargame model – Forcusing on damage assessment of warship,” Journal of KOSSE 17, 1 (2021). [In Korean]
North Korea sank ROKS Cheonan in March 2010; the ship was later raised and put on display (Photo by Larisa Epatko/PBS NewsHour)

Although the article is in Korean, many of the graphics are in English, and figuring out what the various algebraic equations likely relate to is possible in places. As I read what I could in the article, it struck me that I had seen much of this before from the Admiralty Trilogy Group (ATG), designers of my beloved Harpoon V naval miniatures wargame.

Cheonghae (“Blue Sea”)

The abstract from the Korean article makes it sound like the original ROKN damage model is quite simple; “In existing model, the Cheonghae, the probability of kill of a warship is calculated simply considering the number of tonnage without any stochastic elements, and the warship’s mission availability is also determined based on predetermined values. I find this a bit astonishing because I can’t think of a single commercial tactical naval wargame in my collection where ship damage is solely a function of tonnage. I mean, even my 1975 version of General Quarters (NavWar Productions) or the 1978 edition of Bismarck (Avalon Hill) has hits against different ship components.

The ROKN study goes on to explain a new methodology that is, “expanded to a comprehensive assessment of wartime warship loss rates by integrating damage rates for personnel, equipment, and supplies in wartime.” While this certainly sounds like a “modern” approach, I have to point out that the damage model in the commercial tabletop wargame Harpoon V already does this through a Critical Hit damage mechanism.

Harpoon V from ATG

Fortunately for naval wargamers who want to understand the Harpoon V damage model, ATG publishes on their website a series of presentations from various conventions they attend. These presentations provide some insight into their games, with more than a few being game design “peek under the hood” content. This allows us to do a limited comparison between Cheonghae and Harpoon V.

ATG Harmonization

In the mid-2000’s, ATG realized that the various damage calculation methodologies used in their three principle games (Fear God & Dread Nought for World War I, Command at Sea for WWII, and Harpoon for “modern”) were unsynchronized. Thus, they embarked on a “harmonization” process. A major component of the harmonization process was a rebuild of the ship damage model in the game.

At the 2006 Cold Wars convention, ATG designer Chris Carlson presented, “Weapons Effects and Warship Vulnerability” (Cold Wars 2006) where he identified weapons damage effects on warships as one of the biggest issues in the Harmonization Process. The conclusion of his presentation shows where they are going:

  • Weapon damage effects across the Admiralty Trilogy games are now consistent with basic physical principles
    • –  Convert all damage mechanisms into energy terms
    • –  Use standard explosive theory equations
    • –  Eliminates model distortions (edge effects)
  • Damage point value changes vary based on weapon type and warhead size
    • –  Torpedoes have the greatest change
    • –  Less so for bombs, shells and missiles
    • –  Smaller warheads become more lethal, very large ones are less

At Cold Wars 2008, Chris made another Admiralty Trilogy Seminar presentation titled, “Variable damage Effects in Naval Wargames” (Cold Wars 2008). This is an excellent review of many popular naval wargame systems and how they model damage. More than a few here use a stochastic model, but it is also interesting to see how many use something more. Again, the conclusion provides great insight into where the ATG designers were going, and maybe also how far ahead of the ROKN:

  • Damage variability is a high interest item for players
    • Variability drivers: Location, warhead performance, secondary effects
    • Admiralty Trilogy games don’t use specific hit locations
    • Warhead performance variability isn’t realistic
    • Secondary effects the best option for our games
  • Damage effects are very difficult to model
    • Significant tension between playability and accuracy
  • Revised model gives greater variability in fire and flooding critical hits and in the DC [Damage Control] die rolls
  • Delayed implementation of some critical hit results means ships aren’t instantaneously crippled

Cold Wars 2012 saw another presentation, “Staying Power: Assessing the Damage Capacity of Ships” (Cold Wars 2012). As the presentation says, “Quantifying damage is vexingly complex, and any approach is hard to defend because it is a subjective estimate.” What follows is another review of historical approaches to solving this problem, and how ATG designers are approaching it for their games. Along the way they identify two main models; deterministic and stochastic:

  • Two main approaches to damage effects modeling:
    • Deterministic Model: A ship sinks when the cumulative damage exceeds the ship’s life
      • NWC [Naval War College] Fire & Maneuver Rules and RN [Royal Navy] 1929 Wargame Rules
      • Combat capability and mobility decreases with damage
    • Stochastic Model: A ship sinks, not from cumulative damage, but from a catastrophic event, such as a magazine explosion or excessive flooding
      • U.S. Navy Bureau of Ordnance developed this model during the war
      • Striking Power of Air-Borne Weapons Study, ONI, July 1944
      • Another way to look at it is as a loss of function model

From the limited portions of the Korean study I can read, it sounds like the original ROKN damage model is Deterministic and the goal of the new Cheonghae version is to add Stochastic elements. The ATG approach to damage in their games always has been to create a hybrid. ATG pointed out—back in 2012—that, “Wargaming is best served by a hybrid approach to damage effects (deterministic/stochastic elements).

What’s Old is New Again

Given that I cannot fully read the new Korean journal report there is a fair chance I am missing something here, but I feel that I’m not far off in saying that Korean modeling & simulation may be a step (or more) behind commercial naval miniatures wargaming. I skimmed the journal article bibliography in the vain hope of seeing some reference to miniatures wargaming but alas, no. I find it a bit ironic that when comparing the damage model in Harpoon V to this Korean study, the Harpoon V model, long begrudged in some wargame circles as “too complex,” is in this case the “simpler” model in that it does not need a computer to run nor overtly resort to all the algebraic functions and the like. If one wants to recreate the math behind the ATG model, you can dig through back issues of ATG’s journal, The Naval SITREP, and find articles that show you the way.

There are some (many?) wargamers out there that proclaim Harpoon V (or any of the ATG games) are more simulation than game. I will rise to the defense of ATG here and say that these complaints have not fallen on deaf ears and the ATG staff makes tremendous efforts to make their games playable. Regardless of what you think about their success in doing so, they should nonetheless be recognized as serious game designers who can really math the wicked problems. One can both play and study with ATG naval miniatures wargames. Both players and researchers could benefit from their work with just a little more attention. Surely, adopting (or even adapting) a commercial-off-the-shelf model is less expensive than all the development work that is going into Cheonghae. More importantly, the ATG staff has worked hard to validate their model—I would like to see what Cheonghae says about many of the same cases ATG modeled. Now that would be a great comparison.

Can you figure out how many Damage Points were inflicted here?

Feature image – Ex-USS Ingraham being sunk a target in Large Scale Exercise (LSE) 21 (courtesy pacom.mil)

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