Odds of a Critical Failure with a Mini-Rail Gun

[Ndreare]

I was just thinking about the odds of critical failure with a mini-rail gun because a player had to roll for it.
These things are super dangerous to use for the owner. They run a very high likely hood of going south. (The same is true for powers where a player has to roll four dice with only 1 bennie such as onslaught.)

So i figured maybe other people would be curious, what do you think? I notice there is not much of a difference between a d4 and a d12. The odds are surprisingly very high for such a common weapon, but I guess thinking about it it makes sense.

d12 Chance of Technical Difficulties

• 6,095 = Events With a 1
  20,736 = Total Events
  29% = Percentage
  16.7% = Events of 1 on Wild Die
  4.90% = Critical Failure

d10 Chance of Technical Difficulties

• 3,439 = Events With a 1
  10,000 = Total Events
  34% = Percentage
  16.7% = Events of 1 on Wild Die
  5.73% = Critical Failure

d8 Chance of Technical Difficulties

• 1,695 = Events With a 1
  4,096 = Total Events
  41% = Percentage
  16.7% = Events of 1 on Wild Die
  6.90% = Critical Failure

d6 Chance of Technical Difficulties

• 671 = Events With a 1
  1,296 = Total Events
  52% = Percentage
  16.7% = Events of 1 on Wild Die
  8.63% = Critical Failure

d4 Chance of Technical Difficulties

• 175 = Events With a 1
  256 = Total Events
  68% = Percentage
  16.7% = Events of 1 on Wild Die
  11.39% = Critical Failure

So was my process correct or did I do something wrong?

[Kuikku]

Though your math looks right, skill die of 1 divided by times rolled, I find the resulting percentages rather high. Based strictly on probability rolling a d10 skill should come up a 1 about 10% of the time. Your test sample has 1s showing up more than three times the statistical average. In fact all your "skill roll 1" percentages are between 2.5 and 4 times higher. Oddly enough your wild die rolling a 1 is exactly right. The numbers should be more like:

d12
Chance of 1: 8.33%
Wild Die of 1: 16.67%
Crit Fail: 1.38%

d10
Chance of 1: 10.00%
Wild Die of 1: 16.67%
Crit Fail: 1.67%

d8
Chance of 1: 12.50%
Wild Die of 1: 16.67%
Crit Fail: 2.08%

d6
Chance of 1: 16.67%
Wild Die of 1: 16.67%
Crit Fail: 2.77%

d4
Chance of 1: 25.00%
Wild Die of 1: 16.7%
Crit Fail: 4.16%

Again, based on strict statistical probability. And if you look at these numbers you can see that a d12 has about one third the odds of a crit fail that a d4 does.

I presume your got your numbers from the roll records here on site. If so there may need to be a test of the RNG being used to verify its veracity.

[Ndreare]

Though your math looks right, skill die of 1 divided by times rolled, I find the resulting percentages rather high. Based strictly on probability rolling a d10 skill should come up a 1 about 10% of the time. Your test sample has 1s showing up more than three times the statistical average. In fact all your "skill roll 1" percentages are between 2.5 and 4 times higher. Oddly enough your wild die rolling a 1 is exactly right. The numbers should be more like:

The results you are showing is for only rolling a single die. My odds were calculated for rolling 4 dice and having one or more of those 4 dice show a 1 and the Wild Die show a 1 at the same time. It is a critical failure if the Wild Die and Any Other Die shows a 1.

The idea is to show the riskiness of using a 4 bolt onslaught or a TX50. Because once it happens you cannot bennie to undue the result.


Edit: For normal rolls consider checking out the following I put together for playing Echo. http://savagerifts.com/sr/viewtopic.php ... 889#p15889

[Radecliffe]

Though your math looks right, skill die of 1 divided by times rolled, I find the resulting percentages rather high. Based strictly on probability rolling a d10 skill should come up a 1 about 10% of the time. Your test sample has 1s showing up more than three times the statistical average. In fact all your "skill roll 1" percentages are between 2.5 and 4 times higher. Oddly enough your wild die rolling a 1 is exactly right. The numbers should be more like:

The results you are showing is for only rolling a single die. My odds were calculated for rolling 4 dice and having one or more of those 4 dice show a 1 and the Wild Die show a 1 at the same time. It is a critical failure if the Wild Die and Any Other Die shows a 1.

The idea is to show the riskiness of using a 4 bolt onslaught or a TX50. Because once it happens you cannot bennie to undue the result.


Edit: For normal rolls consider checking out the following I put together for playing Echo. http://savagerifts.com/sr/viewtopic.php ... 889#p15889

Yeah, the same thought occurred to me when I did my Power Armor Soldier and I used the same methodology. The results are a little disconcerting especially considering with rail guns you have fire using the max rate. At least the heavier guns have a RoF of 3 so at a d10 Sparky "only" has crit fail rate of 4.52%

[Kuikku]

My odds were calculated for rolling 4 dice and having one or more of those 4 dice show a 1 and the Wild Die show a 1 at the same time.

Somehow I missed that crucial point. Any automatic weapon will have higher chances of Crit Fail of course. I just did not realize how much higher for even a ROF 4 weapon.

This makes even a three shot Bolt much less appealing.

[Ndreare]

My odds were calculated for rolling 4 dice and having one or more of those 4 dice show a 1 and the Wild Die show a 1 at the same time.

Somehow I missed that crucial point. Any automatic weapon will have higher chances of Crit Fail of course. I just did not realize how much higher for even a ROF 4 weapon.

This makes even a three shot Bolt much less appealing.

That is what I was thinking. I don't want my turn to end with me being shaken.