tag:blogger.com,1999:blog-2170237526012357403.post1368428001656685310..comments2024-03-15T11:16:44.045-04:00Comments on Delta's D&D Hotspot: What is the Best Combat Algorithm?Deltahttp://www.blogger.com/profile/00705402326320853684noreply@blogger.comBlogger73125tag:blogger.com,1999:blog-2170237526012357403.post-62062000185842470582023-03-23T09:59:55.809-04:002023-03-23T09:59:55.809-04:00I know it's very late to comment on this, but ...I know it's very late to comment on this, but the assumption being made is wrong. The player only knows their roll and their modifiers. They then tell their total to the DM who knows the AC and declares a hit or miss. Target20 is a great system I've used for years and does actually run faster than ascending AC for the reasons stated in this blog.Rob of the Northhttps://www.blogger.com/profile/08970111441532206496noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-22286418482138455732021-10-17T11:16:23.385-04:002021-10-17T11:16:23.385-04:00Hey, thanks for sharing that! It's funny, in m...Hey, thanks for sharing that! It's funny, in my heart I honestly orbit around want a low-roll mechanic just like that a whole lot. Just a month ago I wrote in the <a href="https://deltasdnd.blogspot.com/2021/09/d6-usage-in-od.html" rel="nofollow">d6-mechanic post</a>, "So there are days when I wistfully daydream of a D&D tradition in which all the mechanics were always roll-low by default..."<br /><br />The really clever thing you've got there is maintaining the nat-20 as an "ace" success, that's very clever! That said, I'm always feel blocked at making that switch due to everyone's long-standing expectation for D&D of a roll-high mechanic on the d20. :-/Deltahttps://www.blogger.com/profile/00705402326320853684noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-74855749554849824952021-10-11T07:00:17.895-04:002021-10-11T07:00:17.895-04:00Hello Delta. Doing necromancy from 2021.
I figure...Hello Delta. Doing necromancy from 2021.<br /><br />I figured an algorithm that follows those principles and cuts some math further, with some extra perks. Target 20 was mentioned so I'm sharing it with you so you tell me what you think of it.<br /><br />https://www.reddit.com/r/osr/comments/q5sqiu/rollunder_algorithm_for_acDresdomhttps://www.blogger.com/profile/03417300718374616509noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-77174230917444905242021-05-14T14:21:36.398-04:002021-05-14T14:21:36.398-04:00Glad to see Mike Mearls keeps up with the OSR...Glad to see Mike Mearls keeps up with the OSR...Fanfanhttps://www.blogger.com/profile/14047931982239997873noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-23463538673416262262019-02-16T10:41:06.369-05:002019-02-16T10:41:06.369-05:00Oh, yeah, that's a good catch. Thanks for post...Oh, yeah, that's a good catch. Thanks for posting the correction!Deltahttps://www.blogger.com/profile/00705402326320853684noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-90884402113624761972019-02-15T12:42:14.572-05:002019-02-15T12:42:14.572-05:00Apparently, past step c), I should of have changed...Apparently, past step c), I should of have changed the orientation of the great-than sign, as follows:<br /><br />original c)<br />(d20+mods+level-20)*(-1) ≥ (-AC)*(-1)<br /><br />original d)<br />20 - d20 - mods - level ≥ AC<br /><br />When it should have been:<br /><br />original c) [re-type]<br />(d20+mods+level-20)*(-1) ≥ (-AC)*(-1)<br /><br />corrected d)<br />20 - d20 - mods - level ≤ ACIgor da Silva Livramentohttps://www.blogger.com/profile/02573014189087408962noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-87136469012788171782019-02-10T22:31:23.195-05:002019-02-10T22:31:23.195-05:00I think that's a good observation, and I agree...I think that's a good observation, and I agree! See if you can't get your players to at least try the Target 20 method... It's usually a pretty easy sell once they see they can just positively add their modifiers, instead of the reverse-subtraction needed with THACO. :-) (If they're sticklers for math, send them <a href="http://www.oedgames.com/target20/" rel="nofollow">here</a> and they can get as much as they want.) Deltahttps://www.blogger.com/profile/00705402326320853684noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-64005270384537275762019-02-10T20:00:46.819-05:002019-02-10T20:00:46.819-05:00Thank you for the quick and clear reply. I still g...Thank you for the quick and clear reply. I still get amused by such politeness on the internet.<br /><br />I was just trying to easen calculations on my (Game Master) side. But it seems Target 20 is the best system so far.<br /><br />I am running a THAC0 table right now (next session next sunday, feb. 17th) because the players asked it so, it is not that bad, but still takes a bit of time. Target seems the best so far, because it is a quick comparison (because 20 is a rigid, unchanging value, not much fluctuating, excellent).Igor da Silva Livramentohttps://www.blogger.com/profile/02573014189087408962noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-91239259894023426802019-02-09T11:09:36.977-05:002019-02-09T11:09:36.977-05:00Your work looks all correct to me. With classic do...Your work looks all correct to me. With classic downward-improving AC, if you want AC isolated on the right-hand-side, then unfortunately you are going to be doing a bunch of subtractions. That is certainly the motivation for (i) me in <a href="http://www.oedgames.com/target20/" rel="nofollow">Target 20</a> keeping AC as an addition on the left [as in your (a)], or (ii) newer games redefining AC as upward-improving, so as to flip all the negatives to positives [compared to your (d)].<br /><br />What's the motivation for needing AC isolated on the left? Have you tried out the <a href="http://www.oedgames.com/target20/" rel="nofollow">Target 20</a> system in practice (remembering the DM does the add-AC step)? Many of us don't want to go back once we've tried that out a little bit. Deltahttps://www.blogger.com/profile/00705402326320853684noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-36226269185874652952019-02-09T04:32:15.406-05:002019-02-09T04:32:15.406-05:00Can you help me? I am trying to devise a system th...Can you help me? I am trying to devise a system than runs ONLY against the opponent's AC. Let me show you my poor calculations.<br /><br />a) d20 + mods + level ≥ 20 - AC<br /><br />b) d20 + mods + level - 20 ≥ 20 - 20 - AC<br /><br />c) d20 + mods + level - 20 ≥ - AC * (-1)<br /><br />d) 20 - d20 - mods - level ≥ AC<br /><br />Unless I can ignore that (- AC) on c) because that is really how it is, then I would be spared the need to recalculate everything else via subtraction. Am I doing something wrong, or am I doomed to work with subtractions on the left hand side?Igor da Silva Livramentohttps://www.blogger.com/profile/02573014189087408962noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-81122743172114869512016-06-13T19:22:09.550-04:002016-06-13T19:22:09.550-04:00Ha! Well yes... although that 19 changes depending...Ha! Well yes... although that 19 changes depending on level, of course. So I do like getting rid of the whole THACO stat and just remembering to "add your level", basically (esp. for monsters from the DM side). Deltahttps://www.blogger.com/profile/00705402326320853684noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-84413690893315831592016-06-09T17:38:28.336-04:002016-06-09T17:38:28.336-04:00Target 19!?
Dear Delta, I was just reading in Troy...Target 19!?<br />Dear Delta, I was just reading in Troy Denning's old version of "The Classic D&D Game" and what do I see?<br /><br />"Using THACO is often an easier way to remember combat rolls. THACO stands for "To Hit Armor Class 0." The Character Hit Roll Table shows what a character needs to hit Armor Class 0. For instance, a 1st-level fighter needs to roll 19 or better to hit a target with Armor Class 0. Instead of looking on the Hit Roll table for every attack, the player only needs to remember that the character's THACO is 19. Whenever that fighter attacks, the player rolls a d20 as usual. Then any combat modifiers are added, like bonuses for magical weapons or ability score adjustments. Finally, the defender's Armor Class is added. If the total is above the fighter's THACO of 19, a hit is scored. Note that negative Armor Classes will be subtracted from the roll, making them harder to hit."<br /><br />Sound familiar? d20 + AC > 19! Or, rather d20 + AC > THAC0.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-10292461523033544012015-08-07T12:15:59.568-04:002015-08-07T12:15:59.568-04:00Sure, absolutely. But I think that's more than...Sure, absolutely. But I think that's more than outweighed by the majority of times when you'll be adding a positive single-digit number instead (like, all the monsters listed in OD&D). Deltahttps://www.blogger.com/profile/00705402326320853684noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-69232320884180437172015-07-26T12:38:58.295-04:002015-07-26T12:38:58.295-04:00Cool, I'm glad it helped! Your modification so...Cool, I'm glad it helped! Your modification sounds great, too. I'd love to see your even-lighter version of Book of War -- delta at superdan dot net, if you don't already have that.Deltahttps://www.blogger.com/profile/00705402326320853684noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-73439359976680541022015-07-25T21:02:55.162-04:002015-07-25T21:02:55.162-04:00Wow, no wonder I couldn't come up with somethi...Wow, no wonder I couldn't come up with something smooth. I am no mathematician and I would never have figured out that you have to multiply the difference of the CL lvl and the undead HD by 2!<br /><br />Very cool to know now. I like the d6 resolution mechanic. What if we gave a generic +1 for the clerical class, then another +1 per HD. That could render it a "target 6" w/ a d6 much like the corresponding target 20 w/ the d20. The math would be the same as you describe above with a d6 per target 5, right? Just a thought.<br /><br />I ran the wilderness adventure today ("Through Hollow Lands," in Jimm Johnson's Planet Eris campaign). It worked great. If you are interested I can send you my "even-rules-lighter" version of your B of W. We have been using HX and counter rather than minis so I made some mods for that.<br /><br />Anyway, it is awesome to have creative mathematicians in service of our great hobby. Thank you.<br /><br />PeaceTetramorphhttps://www.blogger.com/profile/07253316716885460459noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-75778663410374521502015-07-24T22:10:46.415-04:002015-07-24T22:10:46.415-04:00Oh, and thanks for the comment about your using Bo...Oh, and thanks for the comment about your using Book of War, that's great!Deltahttps://www.blogger.com/profile/00705402326320853684noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-80955108374661996732015-07-24T22:10:24.088-04:002015-07-24T22:10:24.088-04:00Now that's a question I've never gotten be...Now that's a question I've never gotten before! :-) Looking at the Vol-1 table quickly, it seems like the numerical part of the table is equivalent to rolling 2d6 + 2(Clr level - Undead HD), needing a total of 9+ for success. <br /><br />So I suppose I woulds consider collapsing that to 1d6 + Clr level - Undead HD, need 5+ for success? (i.e., base chance 2-in-6.) Obviously, that table has a pretty narrow range where success depends on the roll (so it collapses to a small die). That turns the "T" results into numerical chances (equivalent to having targets 5 or 3 in the table), so you could say if the roll is automatic then you get the "D" result.<br /><br />Alternatively, you could expand it to d20, like d20 + 3(Clr level - Monster HD), target 15+, or something.Deltahttps://www.blogger.com/profile/00705402326320853684noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-81925689009383891222015-07-24T17:16:01.821-04:002015-07-24T17:16:01.821-04:00Thanks, Delta. By the way, I have your book of war...Thanks, Delta. By the way, I have your book of war and I have modified it and put it to use in a hex-crawl I am running right now.<br /><br />Question (perhaps worthy of a blog post?): I know you don't like clerics. But, for the sake of a nice reader like me, can you imagine how the turn-undead mechanic could be cleaned up?Tetramorphhttps://www.blogger.com/profile/07253316716885460459noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-61549914705311832952015-07-23T19:43:34.470-04:002015-07-23T19:43:34.470-04:00Right -- If you're using the original Vol-1 hi...Right -- If you're using the original Vol-1 hit dice for PCs, then that's a very elegant way of doing it (personally I use the revision in Sup-I so it's not quite the same option for me). I'm pretty sure that most of the people in my extended gaming circle do it this way now. Thanks for the input!Deltahttps://www.blogger.com/profile/00705402326320853684noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-47940678255761278102015-07-23T17:10:19.415-04:002015-07-23T17:10:19.415-04:00I'm coming to the conversation late but this i...I'm coming to the conversation late but this is great. I would prefer to base even the PCs on HD rather than Lvl. When they have a "4+1," I would allow the additional bonus. That way you don't have to go back and back divide for clerics and MUs. It powers up the FM too.<br /><br />If I want to keep AC secret, I suppose I could just ask them to tell me their totals, I could then add the AC in my head. Done.<br /><br />So elegant. Thanks much.Tetramorphhttps://www.blogger.com/profile/07253316716885460459noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-6625783918920466182015-03-21T12:18:11.454-04:002015-03-21T12:18:11.454-04:00That's great, thanks so much for the feedback!...That's great, thanks so much for the feedback! Deltahttps://www.blogger.com/profile/00705402326320853684noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-52795992354212895582015-03-21T07:57:35.671-04:002015-03-21T07:57:35.671-04:00I'm running OD&D, 3lbb + some Greyhawk + y...I'm running OD&D, 3lbb + some Greyhawk + your house rules at a con in a fortnight. I've only GMed once before (Cinematic Unisystem, about 8 years ago), so I playtested it to see how it would go.<br /><br />Most of the players were not used to D&D, some had experience but mainly with 3e. I really did not want to use THAC0, as I personally found that system extremely difficult, and resorted to writing my own tables telling me what my die roll would hit.<br /><br />So how did the Target20 hold up? Very well actually. The players added d20 + their (pre-modded) attack bonus, reported the result to me, I added AC, and checked if it passed 20. I didn't use any situational modifiers, but I'd have handled them myself had it come up. However I did sometimes wonder why I was adding, when comparing to an AAC might be quicker. Despite that it was still faster than any 3e game I've ever played, and a little faster than my Basic D&D game where I'm using a table.<br /><br />I'm playtesting again tonight with some board gaming friends, including one person who is totally dyscalculate, so it will be interesting to see how that works out, and if I need to let her just roll the d20 and handle the rest myself.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-85929965931077571362014-12-22T16:15:44.329-05:002014-12-22T16:15:44.329-05:00It is also often OK to let “to hit” progress the s...It is also often OK to let “to hit” progress the same for everyone. The main measure of combat prowess is hp, so if you’re using different HD by class, the fighters will retain an advantage. If you use variable damage by class or variable damage by weapon and restrict what weapons other classes can use, you’ll have that differentiator as well.Roberthttps://www.blogger.com/profile/16733274876782876659noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-47900020137826794442014-12-22T13:07:55.344-05:002014-12-22T13:07:55.344-05:00Good point, I need to remember to include that as ...Good point, I need to remember to include that as a parenthetical note whenever it comes up. I equate "fighter level", as you might guess, to 2/3 the cleric or thief level, and 1/2 the wizard level. <br /><br />Those fractions are the same as 3E, which I settled on because they're easy enough to possibly do in one's head. You could modify them a little to strictly follow other editions. Of course advance documentation can be useful, and it's a minor task because the preponderance of enemies will be fighters or HD-based monsters. <br /><br />See the Target 20 document here for full info:<br /><br /><a href="http://www.superdan.net/gaming/oed/target20" rel="nofollow">http://www.superdan.net/gaming/oed/target20/</a>Deltahttps://www.blogger.com/profile/00705402326320853684noreply@blogger.comtag:blogger.com,1999:blog-2170237526012357403.post-81904753231593886202014-12-21T19:06:03.193-05:002014-12-21T19:06:03.193-05:00I love your algorithm, but I just have 1 question....I love your algorithm, but I just have 1 question. It works great when you add a Warrior's level, because a Warrior goes down 1 Thac0 per level. But what about Priests, Rogues and Wizards? Their attack bonuses don't arrive nearly as quickly as Warriors. So my question is, how do you calculate for the other classes?ジェーソンhttps://www.blogger.com/profile/00956282402652082652noreply@blogger.com