Arden Vul interlude: d12 house rules
No game session this week so I thought I’d take the opportunity to go into a little detail about some of the house rules we’re using. We are running Necrotic Gnome’s Old-School Essentials Advanced Fantasy with the vast majority of the house rules having been borrowed from the excellent list made by the most criminally underwatched actual play series on the internet with a few changes here and there, mostly to adapt to my player group. One of the advantages of playing with the same core group for over three decades now is I have a pretty good idea of how most rules will play at our table without having to extensively playtest.
One place where I did go off script was in OSE’s X-in-6 rolls. Starting with Carcass Crawler #1’s d6 thief skills as modified by 3d6 DTL to include all class skills that were previously percentile based, I then converted all of these to be based on a X-in-12 which is of course just a simple matter of doubling all integers (big thanks to Jon of 3d6DTL of doing the hard work of converting the percentiles to d6 in the first place, and by hard work I mean maths).
So why did I decide to change all of the d6 rolls to d12 (besides just needing to be a special snowflake of course)? A few reasons:
Ease of translation. Any X-in-6 roll can be quickly and simply converted to a d12 roll.
More granularity. I found that having only seven different levels of competence in a given task (including impossibility and certainty; if we include only levels where there is a chance of both success and failure, it’s only five) made it hard to differentiate between different classes in their ability to accomplish a task (aside: I do realize that leaving them as percentages would give even more granularity but at a certain point you start running into false precision; for my purposes I feel like the d12 system offers a good balance between granularity and playability). Converting a 1 in 6 chance to a 2 in 12 chance also allows you to give a character a chance to accomplish something they wouldn’t normally be able to without usurping another character’s class based abilities. For example in the second session of our Arden Vul campaign I decided to allow non-thief characters a 1 in 12 chance to use some thieve’s tools they had found in the ruins of the city to attempt to pick a lock. This is half the chance a level one thief would have even if they had spent no points to improve that skill. An 8.5% chance to accomplish a task is enough so as not to definitively cut off areas or treasure from parties who do not have a thief while also being a low enough chance to not make it a viable full time replacement for those parties. It also allows me to give situational +/-1 modifiers to attempted tasks which is a meaningful bonus/penalty without being too heavy of a swing in either direction.
Having made this change I decided to make the initiative roll a d12 roll as well. Changing initiative to a d12 greatly reduces the chance of a tied roll. This is mostly a benefit to games where tied initiatives are rerolled; having to reroll one out of every six initiative rolls just lengthens combat for absolutely no reason (seriously, if you’re just using side based initiative with no modifiers there’s no reason not to just have each side roll a d20 and have to worry about rerolls way less frequently). I have decided to use the optional OSE rule of tied initiative meaning that actions happen simultaneously; since this will inevitably entail at least a slight slowing down of that combat round I didn’t want it to happen too frequently, so a 1 in 12 chance feels like a good compromise.
I’m trying out a custom Dying mechanic (see above re: special snowflake) using the d12. If a character is knocked to exactly zero HP they are unconscious and out of combat. If they are reduced to negative HP on every turn they must roll a d12: as long as they roll over the absolute value of their negative HP total, they survive. If they roll equal to or less the character dies. (Example: Bunbo the halfling is skewered by a cave troll and reduced to -5 HP. On that players turn they roll a 7 on 1d12; Bunbo lives another round. The next round the player rolls a 5 and Bunbo dies). In this system if a character is barely reduced to negative HP they have a small but non-zero chance of perishing even if it takes a few rounds for another character to render aid. The worse the damage the more likely it is for the character to expire before healing can be applied. Also by not checking until the player’s turn even the most grievous of injuries have at least a small chance of being healed before death occurs.
I honestly just felt like the d12 doesn’t get much love in traditional D&D-based systems. The d4, d6, and d8s all get rolled for HPs, damage, and spell results, d10/d% are rolled frequently as well, and the d20 roll is ubiquitous but the humble d12 has always seemed to get the short end of the stick.
So how are these rules working out at the table? So far so good I think. The only PC death so far happened on a very unlucky roll where the character was at -1 HP and happened to roll a one on their first death check. That player would probably say the system is a failure (sorry Stacey!). No initiative rolls have been tied so far, and for the most part the skill rolls have been made at the same percentage chance as if they were X-in-6 rolls. Obviously still a work in progress, so I will update as the campaign progresses and we accumulate more data. Feel free to drop a comment below letting me know how awesome and/or dumb this is. Thanks for reading and see you next week with (knock on wood) a session 4 recap!