Rules of the Mountain
When I first pitched Shadow of the Weird Wizard as the system for our group's next campaign I mentioned two things I was willing to houserule in now that death was back on the table (coming from Lancer where PC death is very much avoidable): what I called the "mercy rule" and Fortune. The "mercy rule" being that enemies would not target a downed but not dead PC, and Fortune being a metacurrency players could spend to auto-succeed on the Luck roll to get back up. Imagine my surprise when, rereading the Weird Wizard GM book (Secrets of the Weird Wizard), I found that both of those rules were already in the game!1!2 Read the books, kids! There's rules in there.3
One thing that does exist in Shadow of the Demon Lord which I still can't find in Weird Wizard are rules for 'setbacks' and 'opportunities', basically importing a watered-down version of Position and Effect from Blades in the Dark. I especially like the player-driven option where a player can forgo a boon or a bane on a roll4 for an opportunity or setback. My group might not use it, but I want to houserule it in anyway because I like having the option. No idea why it isn't in Weird Wizard by default except maybe for page space?
Shadow of the Weird Wizard seems to use zones by default5 instead of, e.g. 1-yard spaces, which will be something of an adjustment. Most of this group has played Free League's ALIEN RPG before which uses zones (five-ish years ago now), but there wasn't much combat in our ALIEN game so this is going to take some getting used to. I'm hoping it'll make it easier to sketch out battlefields and judge positioning, that's certainly the intent behind the mechanic, but we'll see. The biggest hurdle at first is probably going to be remembering to use zones at all but at least I won't have to worry about scaling maps designed for 5ft spaces to 1yd spaces.
Something else Weird Wizard does that I want to highlight is the way it uses Health and Damage. Health is what D&D would refer to as 'max HP', and Damage accumulates instead of HP decreasing. When a character's Damage total equals their Health, they die or are incapacitated. A character heals all Damage when they Rest, but only 10% of their max Health. This has implications for a hexcrawl, especially as things like traps and falling directly decrease Health instead of just doing Damage. Overall I would expect this to slow down the PCs as they encounter dangers while traveling and at least have to take time to hole up somewhere so they can be at full Health before tackling one of the 'problems' on the map. I love this kind of mechanic (see also my beloved System Strain from Worlds Without Number and, though I don't have direct experience with it, Flesh & Grit from Black Death Rising) as it means that PCs can get into fights frequently without much danger but allows the stakes to instantly be raised as soon as something shows up that directly targets Health. It lets a system emulate the threat of a D&D wight's infamous level-draining touch without actually making a player redo their whole character sheet. Traps (at least the example ones laid out in Secrets of the Weird Wizard) also all affect Health directly, which is brilliant because they give some bite to something that's become kind of rote.6
So despite planning to run a hexcrawl in a system not particularly designed for it I don't anticipate needing to change many rules. I have heard that encounter balance gets wonky pretty quickly in that I will probably have to adjust upwards from the book's recommended encounter difficulties. This would be more of a problem in a traditional Weird Wizard campaign where I would only be running 10 Quests and the players would level up after each one, making encounter balance a constantly-moving target. But since I've got a whole sandbox planned I think I'll get more opportunities to find the sweet spot for my group per level than a regular campaign.
That assumes that balance (i.e. that the PCs will have a reasonable-to-likely chance of defeating each combat encounter assuming they have most of their resources) is desirable which... yeah, it is. Shadow of the Weird Wizard obviously cares about encounter balance given the guidelines in the GM's book and the recent Weird Menagerie vol. 1 with updated and more detailed guidelines. So in the interest of meeting the game where it's at, and to give the players the freedom to tackle the 'problems' in any order they want, I will be matching the challenges presented by the 'problems' to the party's level. On the other hand, to keep some of that hexcrawl spice, there will be dangers with their level fixed from the start that the players can run into before they're ready or when they already outclass those dangers.
I'm running this game because I'm excited to try out Shadow of the Weird Wizard as a ruleset. I like the way characters are made by adding classes on top of each other7, I like what it does with Health as a resource, and I'm even looking forward to trying out zones properly. So: not planning to change much, we'll see how well Weird Wizard fits into the shape of a hexcrawl out of the box.
Secrets, in the Combat section pg. 47: "Enemies ignore incapacitated characters. Avoid finishing off a player’s fallen character unless you have good story reasons for doing so".↩
Fortune is in Secrets under the Rewards section, pg. 50. I was thinking of the Fortune mechanic in Shadow of the Demon Lord which is per-character, but Weird Wizard has Fortune at the party level. It's slightly more powerful for an incapacitated character than Demon Lord's, allowing them to heal all damage and thus get back up instead of just auto-succeeding the check to stand back up.↩
I had a separate post planned out about a problem I remembered from running Free League's ALIEN RPG, only to crack open the Evolved Edition corebook to see that the problem had been fixed, and even in the original edition the way I remembered having to begrudgingly solve this problem comes off as the default solution. There's rules in there!↩
Boons/banes are a pool of d6s, the highest of which is added to/subtracted from a d20 roll.↩
The book says you "can" use zones, but my read is that the game assumes you're using zones given that a 'zone' is a "Size 5 space" and a lot of abilities affect "a Size 5 space".↩
This is actually a baseless claim, I need data - especially from the 5e crowd: how often do you put/come across traps in adventures?↩
Similar to Fabula Ultima, my beloved.↩