Video game weapon critique #2124

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Hello again. I recently watched the Unreal Tournament: Xan episode of Secret Level. If you’ve taken note of my obsession with the video game, you won’t be surprised. It’s not a bad watch¹, especially because it showed an array of the franchise’s weird and wonderful weaponry at work. 

Including, notably, the weapon which I want to talk about this week. This is the Ripper, which is like a cross between an angle grinder, a crossbow, and a grenade launcher:

This was never my first choice of weapon in the game (for one thing, it was usually hard to find), but it is one of the most imaginative and furthest removed from anything in real-life. As we’ll see below, there are good reasons for this. I enjoyed the novelty of bouncing spinning blades off the walls to try to decapitate the enemy, all the time knowing that they could come back in my direction. It wasn’t practical, but it was great fun, as you can see in the clips below (guess which one is the 1999 game and which is the 2024 TV series):

We’ll cover the practicalities of this weapon in the first section today. With tongue firmly in cheek, I think it’s fair to say that this is not the most practical weapon in any military context. In the second section, we’ll look at the secondary fire mode for the Ripper, which makes the discs explode on impact. Finally, we’ll evaluate the Ripper alongside more <ahem> traditional weapons, look at some other similar science fiction offerings, and compare with any real-world equivalents. 

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Spinning blades are cool, but not practical

To start, let’s look at why the Ripper wouldn’t be able to do the cool things it does in the game. In other words, why you would not be able to launch a spinning blade with sniper accuracy to sever an opponent’s head and/or bounce menacingly off the walls.

Boring Reason #1: The Magnus effect

A spinning object creates an asymmetric lift force which pulls at right angles to its axis of rotation. Veritasium has a great video on it (including its practical uses), but see here how it dramatically alters the path of a basketball dropped off a dam:

In the case of the Ripper, the Magnus force will pull the saw blade away from the point of aim, which will make it hard to hit anything further than a few metres away:

We can quantify this effect by making some basic assumptions about the size and speed of the razor blade and using an online calculator. For a blade 30 cm (12″) in diameter, 5 mm (0.2″) thick, and weighing 500 g spinning at 50 revs per second (3000 rpm) and launched at 100 m/s (328 fps), the force would be 27 N (6 pounds of force). This is significant, and would lead to an error of 0.5 m (a person width) at 20 m range, over 1 m at 30 m range, and 14 m at 100 m range. Unless you get used to launching beautiful arced shots, you’re not going to hit anything with these blades.

The Magnus effect has real-life implications for external ballistics, and needs to be taken into account for firing artillery rounds. Speaking of ballistics, there’s another problem with the Ripper…

Boring Reason #2: No spin-stabilisation

Most bullets nowadays are spin-stabilised. I’ll cover this in my upcoming external ballistics lecture entertaining article, but, in short, spinning a projectile about its axis of travel means it’s resistant to forces which push it away, thereby improving accuracy. The Ripper doesn’t have this, so it’s very susceptible to any force which pushes it off its point of aim. Including the Magnus force, as mentioned above.

Combine reason #1 and reason #2 and it’s clear that the Ripper’s razor blades are spinning the wrong way. I think it’s time for another Good Idea, Bad Idea²:

Okay, so we forget about sniper-like accuracy. What about bouncing the blades off the walls?

Boring Reason #3: Real walls break

Real walls aren’t made of adamantium, so a spinning razor blade will do damage to its structure. Yes, I know damage physics isn’t modelled in the game. No walls in this universe are breakable, whether they’re made from brick, concrete, steel, or stained glass:

The problem (and here I’m really nitpicking) is that I can’t accept that the blades ricochet smoothly and repeatedly off all these materials, but slice through heavy armour to cause damage to the enemy. Surely it should bounce off those hardened plates, unless you get the lucky neck shot.

Okay, I hear you say. That’s enough midwit complaining, but I understand that this is a game. We can’t model every intricacy of materials science and external ballistics, so I’ll accept a bit of artistic licence, thank you very much. 

Well, you’re not wrong. Games can be silly, especially shooters. I haven’t given out about the Bio Rifle (yet), and that’s even sillier. Let’s take the game designers at face value, then, and evaluate the Ripper on its supposed effects. Unfortunately, it still comes up short.

Serious reason #1: It’s a weapon designer’s nightmare

The Ripper has a spinning sawblade in an open “barrel,” a railgun-type propulsion system, and a munition that’s part blade, part explosive (more on this below). This weapon is cumbersome, it would be a nightmare to power, and it would pose more of a threat to the firer than to the enemy:

If we had to classify the Ripper from a military standpoint, it would be a short-lived indiscriminate area-denial weapon which the operator needs to deploy manually. In other words, a landmine which you need to fire yourself, or mustard gas which you spray from a can. 

Explosive discs create more problems than they solve

I said I’d deal with the secondary fire before we finished. The Ripper’s alternate ammo also sends spinning saws toward the enemy, but this time the blades explode on impact. Let’s dissect that idea. 

For starters, it isn’t completely impossible, because, as we all know by now, explosives don’t just “go off” on a whim. They need an impetus from a fuze and a small, more sensitive explosive. So you could pack the disk with high explosives and include a selectable fuze:

• Fuze off/inactive: primary fire mode, disk blades only
• Fuze activated: secondary fire mode, with exploding disk

So, kudos for including explosives which sometimes don’t explode. This is progress³. You could even have a centrifugal fuze which initiates when the blade’s spin drops below a certain threshold (i.e. when it hits something). This is an initiation mechanism for some launched grenades in real life.

This is where the problems start, however. Take a look again at the original Ripper, and note how thin the blade is:

It’s going to be hard to pack a decent amount of explosives in there, especially given that the blade must taper out to an edge and consist of at least some solid cutting material. Now we also need to fit a fuze right in the middle (for balance, it can’t be off-centre), along with all the necessary widgets and gadgets for arming. You’ll have a lot of small, expensive moving parts, and very little space for explosives.

This is important, and a serious failing. If you’ve been paying attention here, you’ll know that fragments are the real killers from explosive ammo. Let’s take a look at how fragments are formed during a munition’s detonation:

Most of the explosive power will go into creating fragments from the thin bit of case around the top and bottom of the explosive fill. But there’s not much steel to work with here, because we’ve had to use all our space for explosives⁴, so the fragments are small and light and few. When the detonation wave reaches the edges, finally it has some big fragments (the actual blade) to work with. At this stage, lots of the explosive energy has already gone up and down, so there’s only a small bit left to go “out” and accelerate the fragments of blade. Even then, they only create a single expanding ring of fragment death, rather than the cylinder, cone, or cloud which gives maximum target effect.

In summary, the explosive secondary fire of the Ripper is a giant waste of engineering complexity. Razor blades are a terrible way to deliver explosive energy, complementing its inaccurate and dangerous primary fire.

Conclusion: Just use bullets

I once had a lecturer describe the design journey of caseless ammunition. He said “Every problem which the designers encountered would have been solved if they switched to using a case.” A similar thing is at play here with razor blade ammunition. Every problem, from accuracy, to safety, to explosive fill and fragmentation ability, would be solved if you made it into a bullet shape. There’s a reason ammunition design has trended toward a single universal shape.

In real life, designers stick to the boring but tried-and-tested bullet shape. The one exception I could find is this magnificent (but entirely useless) example built by Joerg Sprave at the Slingshot Channel:

My point here, of course, is not to dump on one of the greatest games of all time. Deathmatch wouldn’t be what it is without the arsenal of exotic weapons we see in Unreal Tournament and similar games. Some of them are semi-plausible and based on real-life weapons, and others are completely out there, but no less enjoyable for that. UT is not alone: there are other games which lean in to bladed weapons such as the tabletop Warhammer 40k with the Eldar Shuriken Catapult⁵.

My point, insofar as I have one (beyond encouraging you, if you’re a fan of UT, to should watch the Unreal Tournament: Xan episode of Secret Level) is to explain some of the real-world physical laws and challenges which dictate what a weapon designer can and can’t do. Sometimes the rule of cool is the only justification for seeing something on the big or small screen, and that’s okay in my book.

That’s all for this week. Thanks for reading and please remember, if you haven’t already, to subscribe using the link below. Please also share this article with a friend. Thanks, and see you next week!

Featured Image: Secret Level – Unreal Tournament: Xan | Ripper, by Lennard Claussen, via Artstation

1. I’m not specifically here to review it, but here’s my hot take, if you’re interested. Firstly, it’s a 15 minute watch, so you really can’t expect too much. Conversely, it won’t demand much of your time so, if you’re a fan of the game, then you should really watch it for the nostalgia. It’s got a simple, neat little story about robots rebelling against their mistreatment by corporate overlords (the infamous Liandri Corporation). It’s mostly action sequences, a series of team deathmatches in familiar UT arenas. The action itself is crisp and satisfying and keeps you nicely distracted from the paper-thin plot. Its shallowness is forgivable, however: it’s 15 minutes long. It features most of our favourite weapons from the game in high definition. Go watch it and then tell me what you thought of it. ↩︎
2. With credit to my former comrade-in-arms who used to sprinkle these gems liberally in ammunition safety lectures. You know who you are. ↩︎
3. Or at least it was, in 1999. Not that anyone else took note: exploding barrels remain a staple of the medium to this day. ↩︎
4. And we can’t fix this by making the case thicker, because this would take away from the explosive space, which in turn would impart less energy to the fragments. You lose either way. ↩︎
5. I’d like to do a deep dive on 40k some day, because there’s such a wealth of cool weaponry in the canon. As an aside, I used to play with Eldar armies, and it annoyed the hell out of me that the Shuriken weapons, with their supposedly advanced alien tech, were weaker in stats than a Space Marine’s boltgun. Oh well. ↩︎