GURPS: The Siege (Part V)

As stated earlier, watching "The Pacific" and "13 Hours" has me thinking about a quasi-realistic siege scenario for the Action! game that we occasionally play on Saturdays. In both of those references, mortar fire plays a pretty big role - heck, one of the Main Characters in "The Pacific" is a mortar-man. So how does this work exactly?


In GURPs, the Artillery skill would be used for mortars, specifically Artillery (Cannon). (This presumes a successful Forward Observer roll.) There would be the usual range penalties to come into play in addition to some specific modifiers but those aren't super relevant in this case. Since I'm focusing on a "real-world" scenario (even though the ConsOps game is set in the Near Future), poking around on the awesome Internet Movie Firearms Database entry for 13 Hours, I see that the attackers used M1 Mortars, which fortunately, has an entry in GURPS: High Tech (p145, under the Stokes ML 3" Mk I, 81mm descriptive text, starting with "The U.S. Army's Watervliet M1 (1937-1945)..."

So, we've got the skill and the equipment. Let's put this into play, shall we? There is simply no way that the guys using the mortars in 13 Hours are anything but Mooks (Action 2, p45-46) which puts them as skill level 10-15. I'm going to go with -13 just for simplicity. Range is the biggest factor, I suspect - if they try to use the mortar from 100 yards away, that automatically drops their effective skill down to 3 which makes a critical failure almost a given. Even firing from 50 yards away has a -8, putting them at effective skill of 5, which is still horrible. Aiming gives them +2 (Acc bonus of the M1), which places them at 7.

However, looking at the weapon chart for the Stokes Mk1/M1 Mortar on High Tech 146 causes me to note that the Range is listed as 275/1,600 with a note that the first range is the minimum range, not 1/2D. This means that they have to be using the mortar with a -13 range penalty, which destroys any chance of them actually hitting a target. Who knew mortar men were that skilled?

So my numbers currently look like this:

• Artillery (Cannon)-13
• Weapon Accuracy: +2
• Presume successful Forward Observer roll: +1
• Range: -13
• Total effective skill: 4.

Ugh. Needless to say, this is terrible. So, in true Action! style, let's streamline it. Let's ignore all of that and instead go with:

• Forward Observer-13. The spotter does all of the work. He has a -3 per 500 yards between him and the target.
• Artillery (Cannon)-13. Make a single roll. Presuming that the roll is successful, the round is successfully fired on the target.

In this way, I can minimize the number of actual rolls that I have to make as GM. That said, artillery is potentially absolutely deadly. We're talking 6dx2 [4d] cr ex here, which is going to ruin even an Action! hero's day. Scatter rules (Basic, p414) should come into play, with the results being applied to the F.O.'s roll. So, for example, if my spotter has a -13, is at exactly 500 yards away (so -3), and rolls a 7, the round hits the target dead center. If, however, he rolls a 14, he missed by 4 yards which is still potentially deadly, what with shrapnel and all.

Urgh. The more I consider it, the more I realize I'm over-thinking this. In this case, mortar fire should just be there to blow up NPCs and maybe throw the Action! heroes back several yards. It may temporarily deafen them, but beyond that, it's probably too lethal to really be used correctly. Perhaps it should just be a plot device? Sort of:

PC: Screw this. We're going to pile into that car and bug out of here. Our daredevil Wheelman can get us clear.

GM: A whistling sound warns you in time to dive for cover as a mortar round lands directly next to the car and explodes which knocks the vehicle on its side and clearly ruins the engine...

Yeah. That's probably the way to go ... less number crunching, less "realism"...