incrdbil Posted July 9, 2018 Report Share Posted July 9, 2018 I've been tinkering with implementing a alternative way to handle combat and skill rolls in an upcoming game. I was seeking input on if it is worth the trouble and if its statistically faithful and doesn't screw up success/failure chances. So, the Combat Mechanic is OCV +3d6 roll against DCV + 10. For the player, its maybe a little less complicated. He isn't adding then subtracting, he simply announces the target DCV number he hit. Already, I sense people saying that should be DCV+11. Since I'm going to a roll a number or higher, instead of a certain number lower, I have to start at 10 to get the same percentage results. (the cumulative chance to roll a 11 or ess is 62.5%; rolling a 10 or higher is 62.5% So in my formula, instead of subtracting 3d6, adds it to OCV to hit a target number of DCV +10. Working it out: Compare an OCV of 9, to a DCV of 8. Standard method. (9+11)-3d6 to hit a DCV of 8. So, as long as you roll a 12 or less, you score a hit. (Total is 20, if you roll a 13 or higher, you've missed DV 8). Percentage wise, you have a 74.1% success of chance on 3d6--the cumulative chance of rolling a 12 or less on 3d6. My method. 9+3d6 versus 8+10. You hit if you get a roll of 9 or better, which happens 74.1% of the time. Works out for many other values I've compared. Critical hit rules: these are problematical. right now, I'm looking at a Critical happening when you exceed the target number by 9, which would make them non-existent on rolls where CV's are equal, so I'll retain the rule that 18 is always a critical. It skews for fewer criticals until you get to a 4 point CV difference; at the 7 point level difference it starts yielding more criticals. at 8 points, its 50% percent critical hits as opposed to a 37.5% of the time for the standard method (at least most of the time, certain values fudge with this a bit). A ten point difference yields drastically more crits--83% of the item as opposed to 50%. But ten point differences are going to be rare. It may be simpler to simply say 18 is a critical, 3 is a fumble. Or for every 3 point difference between OCV and DCV, lowers the critical roll by 1. Crits are annoying complications. Any suggestions for crits in this system, I'd love to hear. Now for Skill resolution You add the value of your skill (its no longer a less, just a value) to a 3d6 roll. You announce the Skill target number you hit. So if you skill is 12 , and you roll an 8, you announce you hit Skill target number 20. A zero modifier skill roll (ie, the player has no penalties or bonus) is a 21. So a player with a skill of 11 needs to roll a ten or higher to succeed for an unmodified check. The player in the example above failed by one, he needed a nine or better. Stat check traditional skill: 11 or less happens 62.5% of the time. 10 or higher happens 62.5% of the time. 8 or less skill: traditional method happens 25.9% of the time. Skill 8 needs to roll a 13 or higher to hit the standard skill target number of 21, which happens 25.9% of the time. Target numbers go up as follows. Standard Hero Skill Modifier Value New Target Number Value -5 Penalty to Roll 26 -4 Penalty to Roll 25 -3 Penalty to Roll 24 -2 Penalty to Roll 23 -1 Penalty to Roll 22 Base Skill Roll 21 +1 Bonus to Roll 20 +2 Bonus to Roll 19 +3 Bonus to Roll 18 +4 Bonus to Roll 17 + 5 Bonus to Roll 16 so if you have a 14 or less skill, and you are trying to beat a target an extremely difficult lock; the GM assigns it a -5 modifier under the old system. Old system 14-5 is a 9 or less. 37.5% chance of success. This system, your target number is 26. you have to roll a 12 or higher, which happens 37.5% of the time. Opposed Rolls become easy. Roll and remember, no need to calculate margin of success. Highest roll wins. Thoughts, problems, things I've overlooked, or screwed up? For reference--3d6 probability chart. 3d6 Roll Chance of result % roll equal or below % roll equal or above 3 0.50% 0.50% 100.00% 4 1.40% 1.90% 99.50% 5 2.80% 4.70% 98.10% 6 4.60% 9.30% 95.30% 7 6.90% 16.20% 90.70% 8 9.70% 25.90% 83.80% 9 11.60% 37.50% 74.10% 10 12.50% 50.00% 62.50% 11 12.50% 62.50% 50.00% 12 11.60% 74.10% 37.50% 13 9.70% 83.80% 25.90% 14 6.90% 90.70% 16.20% 15 4.60% 95.30% 9.30% 16 2.80% 98.10% 4.70% 17 1.40% 99.50% 1.90% 18 0.50% 100.00% 0.50% Expanded skill chart and probabilities of success 21 is a standard target number for an unmodified skill roll. Current Hero System Skill Modifier +5 +4 +3 +2 +1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 Skill Target Number Skill Roll 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 3 25.90% 16.20% 9.30% 4.70% 1.90% 0.50% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 4 37.50% 25.90% 16.20% 9.30% 4.70% 1.90% 0.50% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 5 50.00% 37.50% 25.90% 16.20% 9.30% 4.70% 1.90% 0.50% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 6 62.50% 50.00% 37.50% 25.90% 16.20% 9.30% 4.70% 1.90% 0.50% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 7 74.10% 62.50% 50.00% 37.50% 25.90% 16.20% 9.30% 4.70% 1.90% 0.50% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 8 83.80% 74.10% 62.50% 50.00% 37.50% 25.90% 16.20% 9.30% 4.70% 1.90% 0.50% 0.00% 0.00% 0.00% 0.00% 0.00% 9 90.70% 83.80% 74.10% 62.50% 50.00% 37.50% 25.90% 16.20% 9.30% 4.70% 1.90% 0.50% 0.00% 0.00% 0.00% 0.00% 10 95.30% 90.70% 83.80% 74.10% 62.50% 50.00% 37.50% 25.90% 16.20% 9.30% 4.70% 1.90% 0.50% 0.00% 0.00% 0.00% 11 98.10% 95.30% 90.70% 83.80% 74.10% 62.50% 50.00% 37.50% 25.90% 16.20% 9.30% 4.70% 1.90% 0.50% 0.00% 0.00% 12 99.50% 98.10% 95.30% 90.70% 83.80% 74.10% 62.50% 50.00% 37.50% 25.90% 16.20% 9.30% 4.70% 1.90% 0.50% 0.00% 13 100.00% 99.50% 98.10% 95.30% 90.70% 83.80% 74.10% 62.50% 50.00% 37.50% 25.90% 16.20% 9.30% 4.70% 1.90% 0.50% 14 100.00% 100.00% 99.50% 98.10% 95.30% 90.70% 83.80% 74.10% 62.50% 50.00% 37.50% 25.90% 16.20% 9.30% 4.70% 1.90% 15 100.00% 100.00% 100.00% 99.50% 98.10% 95.30% 90.70% 83.80% 74.10% 62.50% 50.00% 37.50% 25.90% 16.20% 9.30% 4.70% 16 100.00% 100.00% 100.00% 100.00% 99.50% 98.10% 95.30% 90.70% 83.80% 74.10% 62.50% 50.00% 37.50% 25.90% 16.20% 9.30% 17 100.00% 100.00% 100.00% 100.00% 100.00% 99.50% 98.10% 95.30% 90.70% 83.80% 74.10% 62.50% 50.00% 37.50% 25.90% 16.20% 18 100.00% 100.00% 100.00% 100.00% 100.00% 100.00% 99.50% 98.10% 95.30% 90.70% 83.80% 74.10% 62.50% 50.00% 37.50% 25.90% Quote Link to comment Share on other sites More sharing options...
eepjr24 Posted July 9, 2018 Report Share Posted July 9, 2018 This seems more complex than the "21-" method I have seen used by others. To make the rolls greater than instead of less than, just subtract the normal Hero roll from 21. So if your normal INT is say 11, your perception roll would be 11- in the less than system, 10+ in the greater than system. For combat, you roll 3d6, add your OCV and modifiers. Your target is DCV+10. That said, your numbers above seem numerically sound, just more complex. - E Quote Link to comment Share on other sites More sharing options...
incrdbil Posted July 9, 2018 Author Report Share Posted July 9, 2018 10 hours ago, eepjr24 said: This seems more complex than the "21-" method I have seen used by others. To make the rolls greater than instead of less than, just subtract the normal Hero roll from 21. So if your normal INT is say 11, your perception roll would be 11- in the less than system, 10+ in the greater than system. For combat, you roll 3d6, add your OCV and modifiers. Your target is DCV+10. That said, your numbers above seem numerically sound, just more complex. - E The 3d6, add your OCV and modifiers to hit DCV+10 is what I was proposing above. Glad to see others adopting it. And yes, the subtract from 21 is essentially what I was proposing above, just worded simpler. I was just notign how the target number goes higher based on the skill difficulty..but yeah, just stating the number is always 21, and penalties are to the roll is easier. Ok, others have done it, math must checked out..so adopting it for my campaign. Quote Link to comment Share on other sites More sharing options...
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