Author Topic: UPV Calculations  (Read 2050 times)

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Offline Clark

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UPV Calculations
« on: April 29, 2011, 08:32:16 PM »
With a nod to Tony Lin, I have posted the actual Excel spreadsheet I worked off of to calculate UPVs for weapons into the media gallary.  You will notice that some of the UPVs don’t match the published numbers.  That is because this copy was made sometime in between the publication of the Alien Sourcebook and Junction Point.  The final version was lost due to a computer crash.

Here is a guided tour:

Start with the fields AB2:AD26  Here I estimated the cumulative chance that figures would be engaging each other at a particular range or less.  For obvious reasons, the percentages are different for indoors and out.

AF11:AH15 Is an estimation of how often one might find themselves firing at anywhere from +1 to -2

AF16:AG16 Assigns a value to a pin as percentage of a kill.

AI2:AI8 Is a fudge factor that accounts for the fact that weapons with Point Blank ranges or better are particularly nasty while Lances, Ppshs etc with their 5+ or 6+ kill numbers are a bit weaker.

AG2:AG8 calculates the firepower of a single die at that particular range, assuming autofiring is available as an option, based on the number of pips that could score a kill. It takes into account AF11:AF15 and AI12:AI18.

AH2:AH8 Does the same as above but factors in the value of a pin.

Columns N to T calculate the firepower for each range (PB+ to XX) by taking the difference in percentage between that range and the previous range as found at AB2:AD26, then multiplying by the firepower from AG2:AG8.

Columns U to AA does the same thing but for the outdoor numbers.

At J34 & K34 I calculated the firepower for the Deadbolt Launcher by summing N34:T34 and U34:AA34.  This weapon was considered the baseline and assigned a value of 20 UPVs.  For the other entries in Columns J and K, they sum columns N to T and U to AA, divide by the Deadbolt Launcher’s firepower, multiply by 20, and then multiply by the ROF.  Weapons with the “Does not use GMs” quality are then multiplied by 1.25.

The other entry of note is the FOD or Finger of Death.  This is a theoretical weapon that could score a kill on any roll from 1 to 6 out to range 75.  Therefore, it has a firepower of 6, and then the UPV is calculated based on that.  The FOD% columns – L & M – (aka “The FOD Factor”) compare the UPV of the weapon to the FOD UPV to give an idea of just how frickin’ deadly it is.

What I wanted to discuss is the underlyiing assumptions that go into the calculations:

1) Ranges and the chances of engaging at each range
2) Modifiers and the chance having anywhere from +1 to -2
3) The "Fudge Factor" to account for weapons with particularly high or low kill numbers
4) What is a pin worth compared to a kill?

Offline Clark

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Re: UPV Calculations
« Reply #1 on: April 29, 2011, 08:53:15 PM »
For 3), the math works like this: a high ROF / high kill# weapon generates the same average number of kills, but actually has a lower chance of scoring the first kill, which is usually the more important consideration unless you are fighting Fiends and RXS.  That's not considering pinning (which only makes things worse).

For instance, a Deadbolt Launcher at short range using autofire with no other modifiers scores an average of 0.67 kills and has a 56% chance of scoring at lease one.  For a Lance, not autofiring, the average of 0.67 kills is the same, but the chance of scoring at least one is only 52%.  If the Lance autofires the average stays the same (using the upgraded roll rule any 6 becomes a 7 on a second roll of 4+) but the chance of scoring at least one drops to 50%.  So fig for fig, the Lance has about 10% less firepower, unless you can spreadfire or attack Fiends to give your Lancers the chance of scoring multiple kills.

With a -1 modifier, the DBL has an average kill and kill chance of 0.33.  For the Lance, the average is 0.33 but the kill chance is only 0.29 or 29%.

With a -2 modifier (or firing at longer ranges) it becomes more severe.

With using pinning, it gets really whacked.  Assume a shot from 25" with no modifiers.


Normal fire: 16% to pin, 33% to kill
Autofire: 31% to pin, 31% to kill


Normal Fire: 29% to pin, 29% to kill
Autofire: 37% to pin, 20% to kill.

But any further penalties buggers it up because the system doesn't allow for a roll higher than 8.

Offline rcbecker1

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Re: UPV Calculations
« Reply #2 on: July 02, 2012, 05:36:37 PM »
In my opinion I would make the rules universal so people can point out other figures so it works with any minis. This opens up the game for other people to play the game. Also it makes the system more viable to more scenarios and armies.