Time-to-kill: A nerd's guide to submarine weapons

[For version 1.0.13.1] An attempt at distilling Barotrauma's myriad weapons systems and complicated damage model to a simple question: How long does it take to kill?

Introduction

The game Barotrauma presents players with myriad options for submarine weapons and ammunition types, each with unique attributes that allow it to excel or falter against Europa’s dangerous wildlife. Each ammunition type has its own set of “afflictions” built on top of a complicated damage model, are fired at varying rates from various submarine-borne weapons, and imposes its own logistical challenge to field them.

To simplify matters and help players make a more informed decision on their weapon and ammunition choices, this guide seeks to distill all the above to one “simple” metric: How long does it take to kill a hostile creature?

Testing - as explained in detail in the methodology section below - was done by setting up a firing range using latchers, molochs, and endworms as static targets; shot at from a gun supplied with enough ammunition to avoid to the need to reload until the creature is dead. Ammunition consumption is then tallied or calculated based on an average of three tests, and time-to-kill is calculated from that based on stock rate-of-fire values.

Results

For the purpose of testing, the latcher is chosen as a model organism for an unarmoured Europan wildlife; the moloch as a model for an armoured one, and the endworm as an armoured one for weapons where the moloch dies too quickly to be a useful test subject.

Testing was done by shooting the latcher in the mouth, the moloch in the shell, and the endworm in the side.

Kill times (in seconds) are presented in the tables below. Less is better. There are important caveats as laid out in the discussion section below.

Table 1: Time-to-kill sorted by average kill times against a latcher.

Table 2: Time-to-kill sorted by average kill times against a moloch.

Table 3: Time-to-kill sorted by average kill times against an endworm.

Supplementary data including ammunition expenditure against each test subject is available from this Google Doc spreadsheet[docs.google.com]. The data presented above is also available in a different format in the supplementary data file that may further aid data interpretation.

Discussion

When considering the kill time against various Europan creatures, the effectiveness of submarine-borne weapons can vary several-fold even for the same weapon depending on the opponent and the ammunition supplied. A proficient crew should consider this factor in deciding how to equip their submarine for hostile encounters with Europan wildlife.

There have been weapons comparison tests done by the Barotrauma gaming community before, most notably by the Youtuber InitialDesu. To the author’s knowledge, however, this is the first attempt at testing all submarine-borne weapons (except depth charges) against a common metric, for the same (current as of May 11, 2023) version of the game. Additionally, the results have been averaged across three tests to better approximate typical kill times that can be expected.

Nevertheless, there are several shortcomings to the test setup that should be considered in interpreting the results.

Generally, these results should only be considered a theoretical minimum that can be expected of each weapon system under idealised conditions unencumbered by limitations such as ammunition feed and supply, accuracy, and limited opportunities to open fire.

Further limitations are explained below:

• The accelerated nature of the test setup prizes raw firepower at the expense of giving damage-over-time effects little opportunity to shine, thus limiting the data’s usefulness when considering weapons and tactics that do not rely solely on raw firepower.
  
  Bleeding damage is most severely affected by this shortcoming. In addition, non-damage effects like stun are not captured at all.
  
  For example, the test results suggest that a flak cannon equipped with physicorium shells is marginally superior to railguns in killing an endworm. In practice, however, the railgun is the only weapon in the test (except when equipped with canister shells) that can cut an endworm to pieces and cause massive amounts of continuous bleed damage – often enough to end the fight in the submariners’ favour.
  
  
• The test was done using static targets even though many Europan creatures prefer hit-and-run tactics. This again means the test results would downplay the effects of damage-over-time when compared to in-game scenarios.
  
  
• During testing, test subjects were struck repeatedly in the same place without missing. This is an important factor when considering damage against armoured opponents, where the same armour segment is being degraded and the underlying soft tissue is ultimately exploited. In-game scenarios will be less consistent.
  
  
• All shots (and nearly all flak shell fragments) impacted the target. This is rarely the case for in-game scenarios.
  
  
• Tests were conducted against a single large target. This may or may not be informative of a more common scenario of engagements versus swarms of smaller targets. Arguably, the test scenario is not even the "correct" way to use weapons like the flak cannon that excel in tackling swarms due to its spread damage.
  
  
• Ammunition expenditure for some weapons systems (coilgun, chaingun, sometimes the pulse laser) were calculated from the condition of the ammunition box at the end of each test, rather than tallied manually. This can introduce rounding errors in calculating how many shots were fired.
  
  
• Time-to-kill is calculated based on the number of shots fired against a test subject until it dies, using the rate of fire of the stock weapon. In in-game scenarios, the actual time-to-kill will differ if the rate of fire of the weapon has been changed via the Submarine Editor.
  
  
• The test results does not account for the time needed to reload a weapon once ammunition has been expended, which in-game can add much delay especially for the railgun.
  
  
• Some aspects of weapon damage remain untested, such as: Certain railgun payloads (e.g. UEX, Compound N, 40mm grenades, etc), targets obscured by structural components (e.g. crews of hostile submarines, thalamus brains). The latter is a key aspect of the coilgun’s piercing ammunition performance.

Methodology

1. The outpost “Shooting range by 42” is loaded in the Submarine Editor.
   https://steamcommunity.com/sharedfiles/filedetails/?id=2964934577
   
2. The gun being tested is rotated 225° and moved to the bottom left corner of the outpost, and the firing arc is set to range from -5° to 275°.Compared to the original outpost design, this gives space for creatures to drift away after death and make way for the next test subject.
   
   
3. For railgun and flak cannon tests, the rate of fire is increased to one round per second to save time (see implications in “Discussion” section).
   
   
4. Extraneous periscopes and loaders are removed. If appropriate for the test subject and ammunition type, additional loaders (up to 10) are placed, filled with ammunition and linked to the gun.
   
   
5. For convenience, the captain’s spawn point is moved to the remaining periscope.
   
   
6. An invincible wall is placed about 20m left of the gun. This serves a backing during endworm tests to prevent the test subject from being pushed out-of-sight through repeated firing.
   
   
7. Test begins by pressing the “Test” button.
   
   
   Figure 1: The view upon spawning into the firing range for a chaingun test with physicorium ammo.
   
   
8. Upon loading, the F3 key is pressed to bring up console commands and the cheats “lights” and “disableenemyai” are used.
   
   
9. Captain gets on the periscope. The cheat “spawn [creature name] cursor” is used to spawn test subjects. For the latcher and moloch, they are spawned at some distance below the gun. For the endworm, it is spawned at some distance to the top left of the gun’s view such that the creature would present its side to the gun. Note that the distance is sufficiently close that weapons with a degree of spread (such as canister shot from the railgun) will all impact the target.
   
   
10. Firing commences until the moment the creature is dead. When executed correctly, there should be no need to reload.
    
    For railgun tests against endworms, special attention is paid to the moment when the endworm is dismembered, which occurred once or twice in each railgun test (except with canister shot). When this happens, the aim is adjusted upwards to continue causing damage to the remaining portion of the endworm rather than to waste ammunition.
    
    
    Figure 2: Testing a chaingun loaded with physicorium ammo against a latcher.
    
    
    Figure 3: Testing a chaingun loaded with physicorium ammo against a moloch.
    
    
    Figure 4: Testing a chaingun loaded with physicorium ammo against an endworm.
    
    
11. The number of shots fired is counted manually for the flak cannon and railgun, or calculated from percentage condition of the individual ammunition boxes. In the latter case, the formula is:
    
    

    Shots fired = (Total ammo condition at start - Total ammo condition at end)/100*Ammo count per box

    
    In one test, for example, four loaders (ie 400 percent ammo condition at start) were used to each feed a fresh box of shredder ammo (400 shots per box) to a chaingun shooting at an endworm. At the end of the test, each ammo box is at 56 percent condition. The calculation is hence:
    
    

    (400-56-56-56-56)/100*400 = 704 shots

    
    
12. The time to kill is calculated based on the number of shots fired and rate-of-fire figures published on the official Barotrauama wiki, using the following formula:
    

    Time-to-kill = Shots fired/rate of fire

    Reusing the the above example with the chaingun (7.5 rounds per second according to the Wiki), the calculation for the example test subject is:
    

    704/7.5 = 93.9 seconds (rounded up)

    
    
13. The test continues with the next test subject, either by simply spawning it in (in the case of railgun or flak cannon, if there is enough remaining ammunition to kill the next test subject) or by resetting the test scenario. The latter is accomplished by press “Esc” to return to the submarine editor, and then immediately repeat Steps 7 to 12.
    
    
14. Test continues until data has been collected for all weapon/ammo/creature combinations of interest, with three test subjects per weapon/ammo combination in order to derive an average figure.

Changes

Only major revisions are noted here:

• May 11, 2023: Reran test and updated figures for the focused flak shell, due to being nerfed in the 1.0.13.1 patch. Added "Changes" section (ie this section).
  
• May 4, 2023: Initial release based on test conducted on version 1.0.9.0.

[Nutrition]

Would love an update with the nerfs to explosive ammo in 1.4.4.1 Blood in the Water update

[kingmagma111]

Excellent work. The test was well designed and all anticipated/discovered errors were clearly laid out for the convenience of the reader. Graphs were clear and easy to read. Wording was concise.
I am proud to present SunTzull with his PhD in Weapons Development, from the prestigious Klorstan University of Europa.

[SunTzuII]

💖

[H4-D3S]

Due to limitations of the comment section, I need to separate review in two comments

The relevance of the research
5 / 5
Research methodology
5 / 5
Originality/novelty
5 / 5
Scientific/practical advancement
5 / 5
Clarity of the paper and layout design
Everything is fine.

[H4-D3S]

The topic of the report
Relevant to the chosen conference section

Comments of the reviewer
The author considers the issue of time efficiency by comparing various weapon systems implemented in the game. The author refers to a detailed practical base demonstrating the practical importance of understanding the time costs to eliminate various hostile fauna of Europa. The article then focuses on a detailed enumeration of the limitations used for the experiment. The author specifies the exact formulas and console commands that were used in the study to show the whole process as a whole and give those interested in the study the opportunity to repeat the experiment.

Overall, the article exhibits remarkable quality. It seems to warrant publication without any content revisions. The only point worth correcting is to arrange the chapters in right order and insert References through the article and its end.

There also are practically no discrepancies in the text presentation.

[SunTzuII]

The Charybdis is not protected by armour plates like how mudraptors, molochs and endworms are, so you won't need to consider weapons on basis of their high armour piercing stats or limb severance stats.

Choose your weapon based on how it performs against the latcher, and you won't stray too far off course.

[zelda]

Charybdis?

[SunTzuII]

It's not peer reviewed though 😉

[Katzitän]

A nice little scientific paper. Beautifully presented.