Alternate Dice Interactions

I like playing around with dice. Figuring out probabilities and how they'll change in different circumstances is fun. It's one of the reasons I used to write systems, they let me implement my weird dice ideas and see how they worked. I'm more focused on writing content these days, so I figured I'd share the interactions I haven't gotten around to using yet. They might as well see the light of day now and instead of waiting for some nebulous future game.

Dice interactions are rules that directly interact with the math of a die roll to alter the outcome in some way. Some common ones most folks are familiar with are:

- Being able to reroll
- Replacing a roll result with a pre-rolled value
- Bonuses and maluses
- Advantage and disadvantage

Anything that modifies the dice rolled or the roll's result counts.

Here are some interactions I'd like to see used widely one day:

Step Up/Down

Alter what size die gets used in a roll. Make an ally's d4 roll a d6, or an enemy's roll use a d12 instead of a d20. (This one's already used regularly, but not enough that I'd call it common. I want to see it used even more often.)

Twin

Add a second die of the same size to a roll, turning the linear probability into a triangular distribution. There are already spells and abilities that let you add a specific die size to your rolls to give a variable bonus, but this is more about creating the curve probability than just providing a boost to the roll's result. It lets the player choose to avoid the risk of rolling very low or high and increase the probability of mid-range values. A play it safe strategy.

Pool

Add multiple dice of the same size and turn a single-die roll into a pool. Exactly how many dice are in the pool could be determined based on level, abilities, spell effects, whatever. It's not important. What's more interesting is how to resolve a roll like this. A number of successes-based threshold doesn't make sense for a roll that likely originally had a target number to beat for resolution. The two options that make the most sense to me are:

1) The result is the total of the dice. So a pooled skill check would (likely) have you rolling Xd20 and a pooled damage roll would be Xd[damage die]. It could easily end up being overwhelmingly powerful. It would also have the same mid-range stabilizing effect as Twin since it introduces a bell curve. The more dice you add, the more centralized the curve.

2) The result is one value chosen out of the separate rolled values. So if you roll a pool of 3d20 and get 2, 14, 9, only one of those is your result. There are a few ways you could decide which of the values is chosen. The most obvious is to pick highest or lowest, but that would just make this Advantage/Disadvantage with more dice. That's boring. The better option is that the player chooses which of the values they want to use.

Bulk

Replace the lowest value on a die with the highest so the highest value's probability is doubled. (Ex: On a d4 you'd replace the 1 with a 4 so your possible outcomes are 2, 3, 4, 4.)

Sap

Replace the highest value on a die with the lowest so the lowest value's probability is doubled. (Ex: On a d4 you'd replace the 4 with a 1 so your possible outcomes are 1, 1, 2, 3.)

* The probabilities for Bulk/Sap are different from Advantage/Disadvantage. The -vantage rolls are independent, meaning you still have a 1/X chance of each possible outcome in each roll. For Bulk/Sap the highest/lowest value has a 2/X chance of occurring. The significance of the 2/X probability also changes with the die size and has a much more dramatic effect on smaller dice.

Cycle

Rolls don't have a set die they use. Instead you cycle through the dice in a standard set, either stepping up or down with each new roll. So if you start a session rolling a d20, your next roll will use a d12, then a d10, a d8, d6, then after you roll a d4 you cycle back to a d20.

You can alter the direction of the cycle at any point with abilities/spells/etc to do things like making an enemy go 8-6-4 then reverse direction to 6-8-10 order instead of looping around to 20, or timing it beneficially for an ally.

Spiral

For enemies only. Each time they succeed add a die to their rolls so they have an ever-growing dice pool. The more they succeed, the more likely they are to succeed in the future in a self-sustaining spiral and get more dangerous as time goes on.

What is O5R?

A while back I was talking about how I like 5e, but run it in an O5R way, and was asked "What's O5R?" Turns out that's a perfectly reasonable question because, despite running all my 5e games in the style, I had a hard time pinning down an actual set of rules/rulings and changes that make an O5R game different from vanilla 5e.

I've given it more thought and come up with an answer.

O5R isn't a distinct system, and it's not 5e that's been houseruled into something unrecognizable. It's 5e mechanics lightly molded and paired with the DM style and decisions to create an old-school feel at the table.

So what does that actually look like? The first, most important differences are:

1) Ignore balance.

Challenges don't scale to the PCs' abilities. There are real dangers confronting them and no guarantee that an encounter will be level appropriate. Your players should have to learn to judge if a situation is too dangerous for them, and if it is, to run away.

You should still at least check a creature's CR to see how dangerous it is, but don't treat it as the deciding factor in whether to use a monster or not.

2) Cut out all the standard D&D/WotC lore.

Keep the D&D IP creatures if you want (I love owlbears and rust monsters), but the setting lore gets pitched. No Faerun, no Sword Coast, no Underdark, etc. Can you have an ocean with pirates? Of course! A winding subterranean realm underlying nearly the entire world filled with unspeakable monsters? I'd be disappointed if you didn't! Just make them your pirates and your lightless underground hellscape.

Don't include things just because The Lore says they exist, and don't hesitate to bring out the gonzo. Throw true weirdness into the mix for your setting, give it some wondrous and bizarre style.

(The corollary to this is you have to explain it to your players clearly. Present them with the important setting details so they can make meaningful choices based on the conditions in the world you've made. Do this before the game starts, at session 0 at the very least, to give them plenty of time to ask questions and understand.)

3) Don't let the PCs start bogged down by a lot of backstory. 

Starting characters should be mostly formless. A basic personality and a handful of details like hometown, family business or previous profession, and a like, dislike, or goal is plenty. Let the rest emerge through play and the characters develop instead of coming to the table as an established entity with a specific build in mind.

(Do make sure your players have their characters take a background in the game mechanic sense though. That's a sizable chunk of their abilities. They can reflavor the backgrounds however they like.)

After you've done that, address the more mechanical aspects:

A) Good plans don't roll. 

If players do something clever or come up with an unorthodox plan that might work, reward them. They've done a good job. Their plan works without needing to roll for it. At the very least it should give them a partial success, positioning them to succeed later or to have an advantage in their current situation.

B) Move the focus away from combat.

This ties into ignoring balance because combat is more dangerous now and usually the worst option in a situation. Give players ways to solve their problems beyond "sword." A good way to do it is to put the focus on exploration. Have the PCs go out into the unknown and face obstacles that they literally can't fight. Rockfalls, deep chasms or cliffs, weather, crumbling structures, etc. Present them with things they need to work through or find ways around instead of a band of goblins that'll only slow them down for a few minutes.

There will still be some combat, but you don't need to change any rules or tweak death save mechanics to make it more lethal. You just need to make enemies smart. Have them use tactics, teamwork, have goals to achieve beyond plain slaughter, use the environment to their advantage, and care about their own lives. Sometimes the PCs have to retreat to survive, sometimes it'll be the enemies who cut and run; but it'll only take a few encounters with competent, coordinated enemies to teach your players that combat's not the default reaction and should be avoided if possible.

C) Homebrew! 

Throw your own stuff into the mix, but don't alter the player-facing mechanics. Instead of trying to lop off sections of the system or make radical changes to basic rules, have your homebrew material add to the existing game.

Pay attention to what the players are interested in and create spells and items that play on that. What you make doesn't have to be powerful, just interesting. For example, when my players fought and slew a bus-sized magically mutated scorpion they asked if they could harvest the chitin to make armor. Of course, they could! (I'm so proud of them.) They took some, dragged it back to town, and found someone to work it into gear. The finished armor had the same stats as a breastplate plus a little magic resistance. Not an exceptionally powerful magical item, but better than what they had and cool to them because of the origin.

Same goes for rules. Listen to what the players want to do and find a way to make it happen. The same group of players found several statues and wanted to try auctioning them off, hoping to get more money than they would with a direct sale. So I made auction rules that leave the exact amount of profit up to luck and keeps the party engaged in a mini game.

Whatever you decide to add, be sure it makes the game more fun and the world more wondrous instead of just harsher.

That's mostly it. Also for consideration is:

- Non-standard treasures and loot. Go beyond coins, gems, and magic items. Give out rare plants, harvested monster parts, spell components, and just generally bizarre artifacts that are maybe valuable, maybe powerful, but definitely intriguing.

- Magic is weird. Represent magic as the distortion of reality and entropic strain on time that it is. Encourage players to reskin the existing D&D spells to better suit their characters. Create new ones. Make it abberant and unsettling.

- Characters are beloved, but expendable. Make sure your players know their choices have consequences and you won't shield their characters. Also, let them retire their characters and make new ones if they want.




TL;DR O5R relies mostly on the DM's choices and flexibility to step away from vanilla 5e. They need to put in the thought and effort to apply basic old school concepts in how they run the game and make a world that's both engrossing and incredibly dangerous.

Kilodungeon Definition

One of the things I like most about the OSR is how often old tropes are tossed by the wayside. Ask folks what a gnome is* and watch how many different answers you get. That said, I also like solid definitions. Having a clear category with specific criteria so I can say [a term] and whoever I'm talking to knows exactly what I mean. It makes exchanging ideas easier because everyone is already on the same page.

It's especially useful when describing game materials. Knowing that something is a megadungeon gives me specific information about scale, play style, how much of a commitment is required to use it (either as intended or hacked), and how much game time and enjoyment my players will get out of it.

Right now the terms I see used most often to describe dungeon sizes are:

One-page dungeon: Compact. Quick, light, and easy to use. Will probably get a session out of it, maybe two.

Microdungeon: A few rooms, maybe more than one floor. Quick to prep and run, but probably at least two sessions worth of stuff. Good for a site in a hex crawl.

Dungeon: The standard unit of adventuring space. Needs at least one read-through before running it, two if you're a conscientious DM. It's got multiple levels, plenty of rooms, maybe a distinct ecology of its own, and loot. Sweet, sweet loot. It's large enough to keep a party occupied for multiple sessions, but eventually they'll clean it out and move on.

Megadungeon: This place is your whole campaign. It's a world unto itself, an endless roil of brick, stone, and earthen chambers burrowing ever deeper. If you are lost inside, you'll never emerge. If by luck you find one of the scattered enclaves of safety and life, your descendants will grow never having seen the sun. A megadungeon is a huge commitment for both the DM and the players. Your game is here. You're exploring this endless maze and not going anywhere else. Granted, megadungeons tend to have a lot of variety in the form of factions, different underground ecosystems, and magically warped areas. It's still a lot.

The jump from manageable, discrete dungeon to sprawling, bottomless megadungeon is too extreme; especially when compared to how close in scale one-page and microdungeons are to the dungeon. It's more than a logarithmic step up in scope. We need something in between.

So we have the kilodungeon. A neat, logical step from the main dungeon unit to the mega-.

Let's define it. There's a lot of range between dungeon and megadungeon to cover, so we should give kilodungeons a distinct size/complexity band to fall into. Make it clear where they exist instead of leaving them in a gray haze of being either a massive dungeon or a tiny megadungeon.

The criteria required to be a kilodungeon is:

• 5 to 7 levels
• Multiple paths between levels
• At least 12 rooms/areas per level
• At most 60 rooms/areas per level
• Multiple exits
• A single cohesive theme

So the bare minimum needed to be considered a kilodungeon is 5 levels, 60 rooms, and 2 exits. The maximum possible while still in the range is 7 levels, 420 rooms, and as many exits as you can shake a stick at.

How did I come up with these numbers and requirements?

The level and room counts: I thought about the relative sizes and complexities of the dungeons I've run/been run through and aimed to have the amount of stuff in an average dungeon be roughly equal to one level of a kilo dungeon.

For example, Skerples' Tomb of the Serpent Kings is a solid-sized dungeon. It has 3 levels, 52 keyed rooms/locations, and 4 exits. Ignore the levels and flatten it down into 52 rooms, then make an area like that into 1 level out of 5 to 7. That's the step up in size I'm looking for when going from dungeon to kilodungeon.

The number of levels came from 1) looking at how many levels a dungeon usually has (1 to 3 is what I've seen most, sometimes 4) and wanting to go beyond that, and 2) just being realistic with my upper bound. Once you pass 7 levels or 420 rooms, it might as well be a megadungeon.

The multiple paths and exits: That's just good design. Can you imagine how boring a completely linear delve would be on this scale? Ye gods.

Also kilodungeons are large, but you can find your way out of them eventually. If you die or disappear in a kilodungeon, it's because you fell foul of a monster, trap, or your own poor planning; not because you had to settle down and make a life there after getting lost. It would be like deciding you live at the mall now because you forgot where you parked your car.

A single cohesive theme: The way I see it, a kilodungeon is a distinct, purpose-built structure. It has a specific role or job it was created to fulfill and it does that and only that. The role might be a necropolis, a stronghold, a mine, a magical research facility, whatever. The important thing is that the whole place is dedicated to its single purpose.

Megadungeons can have a wildly varying patchwork of interlocking cities, biomes, and architectural styles that make them feel like underground worlds. You won't find that in a kilodungeon. Kilodungeons have their own distinct flavor and stick to it.

Apart from size, that stylistic difference is what distinguishes a kilodungeon from a megadungeon in my eyes. When something is on the boundary between the two, ask yourself "How much is going on here? Is there one main theme?" If yes, it's a huge kilodungeon. If no, it's a small megadungeon.

*For the record gnomes are 12 foot tall, spindly, fungal beings with leathery skin that eat primarily tar. They are usually very well-spoken and famous for their complex, regionally varied tea culture. You can find them pretty much anywhere, but they're good at hiding, which is strange for something 12 feet tall that smells like hot tar and Earl Grey.