Over on the RPGSite a poster named Cave Bear asked about probabilities for adapting from 2d6 to 2d12. I couldn't easily post the numbers on the forum, so as a temporary measure I'm putting that here. And since H+I uses a 2d6 system it is at least somewhat relevant.
The system in question uses range bands with associated probabilities of
| Range Band 2d6 | P(iin Range) |
| 6~8 for an easy action | 44.4% |
| 9~11 for a doable action | 25.0% |
| 12~15 for a hard action | 2.8% |
| 16+ for a nearly impossible action | 0.0% |
Probabilities for 2d6
| N on 2d6 | Freq(N) | P( N) | P(≤N) | P(≥N) |
| 2 | 1 | 2.8% | 2.8% | 100.0% |
| 3 | 2 | 5.6% | 8.3% | 97.2% |
| 4 | 3 | 8.3% | 16.7% | 91.7% |
| 5 | 4 | 11.1% | 27.8% | 83.3% |
| 6 | 5 | 13.9% | 41.7% | 72.2% |
| 7 | 6 | 16.7% | 58.3% | 58.3% |
| 8 | 5 | 13.9% | 72.2% | 41.7% |
| 9 | 4 | 11.1% | 83.3% | 27.8% |
| 10 | 3 | 8.3% | 91.7% | 16.7% |
| 11 | 2 | 5.6% | 97.2% | 8.3% |
| 12 | 1 | 2.8% | 100.0% | 2.8% |
| 16+ | 0 | 0.0% | 100.0% |
| N on 2d10 | Freq(N) | P( N) | P(≤N) | P(≥N) |
| 2 | 1 | 1.0% | 1.0% | 100.0% |
| 3 | 2 | 2.0% | 3.0% | 99.0% |
| 4 | 3 | 3.0% | 6.0% | 97.0% |
| 5 | 4 | 4.0% | 10.0% | 94.0% |
| 6 | 5 | 5.0% | 15.0% | 90.0% |
| 7 | 6 | 6.0% | 21.0% | 85.0% |
| 8 | 7 | 7.0% | 28.0% | 79.0% |
| 9 | 8 | 8.0% | 36.0% | 72.0% |
| 10 | 9 | 9.0% | 45.0% | 64.0% |
| 11 | 10 | 10.0% | 55.0% | 55.0% |
| 12 | 9 | 9.0% | 64.0% | 45.0% |
| 13 | 8 | 8.0% | 72.0% | 36.0% |
| 14 | 7 | 7.0% | 79.0% | 28.0% |
| 15 | 6 | 6.0% | 85.0% | 21.0% |
| 16 | 5 | 5.0% | 90.0% | 15.0% |
| 17 | 4 | 4.0% | 94.0% | 10.0% |
| 18 | 3 | 3.0% | 97.0% | 6.0% |
| 19 | 2 | 2.0% | 99.0% | 3.0% |
| 20 | 1 | 1.0% | 100.0% | 1.0% |
| 25+ |
With ~ Range Bands for 2d20
| Range Band | P(iin Range) |
| 9-13 for an easy action | 44.0% |
| 14-18 for a doable action | 25.0% |
| 19-20 for a hard action | 3.0% |
| 25+ for a nearly impossible action |
Probabilities for 2d12
| N on 2d12 | Freq(N) | P( N) | P(≤N) | P(≥N) |
| 2 | 1 | 0.7% | 0.7% | 100.0% |
| 3 | 2 | 1.4% | 2.1% | 99.3% |
| 4 | 3 | 2.1% | 4.2% | 97.9% |
| 5 | 4 | 2.8% | 6.9% | 95.8% |
| 6 | 5 | 3.5% | 10.4% | 93.1% |
| 7 | 6 | 4.2% | 14.6% | 89.6% |
| 8 | 7 | 4.9% | 19.4% | 85.4% |
| 9 | 8 | 5.6% | 25.0% | 80.6% |
| 10 | 9 | 6.3% | 31.3% | 75.0% |
| 11 | 10 | 6.9% | 38.2% | 68.8% |
| 12 | 11 | 7.6% | 45.8% | 61.8% |
| 13 | 12 | 8.3% | 54.2% | 54.2% |
| 14 | 11 | 7.6% | 61.8% | 45.8% |
| 15 | 10 | 6.9% | 68.8% | 38.2% |
| 16 | 9 | 6.3% | 75.0% | 31.3% |
| 17 | 8 | 5.6% | 80.6% | 25.0% |
| 18 | 7 | 4.9% | 85.4% | 19.4% |
| 19 | 6 | 4.2% | 89.6% | 14.6% |
| 20 | 5 | 3.5% | 93.1% | 10.4% |
| 21 | 4 | 2.8% | 95.8% | 6.9% |
| 22 | 3 | 2.1% | 97.9% | 4.2% |
| 23 | 2 | 1.4% | 99.3% | 2.1% |
| 24 | 1 | 0.7% | 100.0% | 0.7% |
| 28 or 30+ | 0 | 0.0% | 100.0% |
With ~Range Bands for 2d12
| Range Band | P(iin Range) |
| 11-16 for an easy action | 43.8% |
| 17-22 for a doable action | 22.9% |
| 23-27 for a hard action | 2.1% |
| 28+ for a nearly impossible action |
And here's the picture
Cave Bear here. Thanks!
ReplyDeleteYou are welcome. I didn't explain much so I hope the meaning was clear.
ReplyDeleteIf you are familiar with Excel it is easy to create tables like this and calculate the probabilities.
Nice! As someone who is terrible with probabilities, this is very helpful! Thanks for posting it.
ReplyDeleteI'm glad it was helpful to both of you. :-)
ReplyDelete