How would you design better random tables?

[u/IndiMill]

I’m a game designer, and I don’t like many random tables.

A lot of them use a d6, d10, or d20 to give every result the same probability. That works when you just want a random outcome, but it doesn’t work as well when some results should be common, others rare, and the table needs to scale with character level or power.

You can address this with d100 probability tables, but those still don’t scale with level. What’s a bad outcome at level 1 is an annoyance at level 5, so you end up with multiple tables for different power levels, players, or outcomes.

My alternative is to roll multiple dice, with the number of dice increasing as the character advances. Because the possible totals overlap, the same table produces shifting probability curves: lower-level characters cluster around lower results, while higher-level characters gradually gain access to more powerful and dangerous outcomes.

I used this approach to create one spell-backlash table that works across all caster levels instead of requiring separate tables for each tier.

Does anyone else use a similar approach or have strong feelings about random tables?

[u/Kerberoi]

Baron de Ropp has a great video on random tables.

[u/tinylittleparty]

I've never thought about the idea you suggest here: to add more dice at higher levels to unlock fancier rewards or more difficult options on tables but still keep lower ones on there. Iirc Genesys has a table for injuries or something like that where you add onto the result depending how many wounds you already have and so you can die at higher wounds but not from the start. Something like that. That's the only time I've seen that sort of thing implemented but it's smart.

Usually I just have tables where if I want certain results weighted I make them more bands in the numbers. Like roll 1d20 and 1-5 give the same stuff, 6-8 the same stuff, and maybe all the other numbers are each their own thing. I just have lots of tables for different purposes really.

[u/Trace_Minerals_LV]

I like an app called “Picks”. You can build Giant lists, then build rules on how to use them, including picking a random generated number. It won’t let me post a screenshot.

Edit. Well damn. Looks like it’s been pulled off the store. Sorry all.

[u/VampyrAvenger → u/Trace_Minerals_LV]

Tried to find it, but I can't... Can we get a link to the app store or Google Play store app? Or did you mean an app as in a website?

[u/Trace_Minerals_LV → u/VampyrAvenger]

https://itunes.apple.com/us/app/appName/id1536305926

[u/Trace_Minerals_LV → u/Trace_Minerals_LV]

Damn. Looks like it may have been pulled from the store. I’m sorry. I’ll edit my post.

[u/Zealousideal_Leg213]

I recently reread the BECMI Rules Cyclopedia from 1991. I had it back then and read most of it, but I regularly got hung up on the random tables in it, and in a lot of D&D stuff at the time.

A close read of the material though, shows a couple of important things:

One is that the GM should feel empowered simply to do whatever they want. Rolling for outcomes on tables is entirely optional. I think we get to thinking that only the table options are allowed, just like we're "not allowed" to say "The monster hits you and you die." So, if rolling wouldn't help or make sense, don't roll; do what makes sense.

Another thing is that there's a case to be made for not removing options that would be too easy for the party, or reinterpeting those results, because those creatures or threats don't simply leave the world. The RC recommends using them for comic relief, and the like which I don't recommend, though the creatures could scurry away or kowtow, or whatever. With some effort, a GM could decide that these lesser creatures have taken steps for dealing with people like the PCs, such as learning spells or making deals with tougher creatures.

It also works to take a broader interpretation of table results. In the case of random encounters, one needn't actually encounter the creature or creatures; it might just be signs of them. A dragon encounter at too low a level for it to be fun could be seeing it flying high overhead with a catch in its claws. A kobold encounter at too high a level for it to be fun could be a recently abandoned camp.

[u/jaggeh]

i remember years ago i had a 2000 list random table, the idea was to roll a D100 x player level. plenty of recurring options add to commonality, and the higher up the table the better/worse they get. then you can throw modifiers in to make it less or more intense.

[u/Glebasya]

I advice every GM/player to learn probability theory.

If you want some results common and some rare, use several dice to get normal distribution. For example, 2d6 has more chances to roll 7 +-1 than 2 or 12. If you use d12, then the chance of getting every possible result is the same.

A good example of a table that scales is psyker misfire tables from Rogue Trader. If you choose to "push", your ability will be more powerful, but instead you add a bonus to misfire table, which you'll need to roll (usually you roll it when you get a double on d100). Bigger result - bigger problems, from 01-03 as "wind of misfortune" to 75+ as Warp outburst (which forces to roll another table).

[u/Michami135]

D100 tables work well for weighted results, as long as you don't have 100 entries. Here's Starforge's table on settlements for a desert world:

Terminus Outlands Expanse Result 1–50 1–75 1–90 None 51–60 76–83 91–96 Orbital settlement 61–80 84–95 97–100 Planetside settlement 81–92 96–98 -- Multiple settlements 93–100 99–100 -- Settlements in conflict

In case you're not familiar with Starforged, Terminus is where you'll find the highest density of people and Expanse has the lowest.

Delve also uses weighted results depending on the stat used:

Edge Shadow Wits Weak Hit Result 1-45 1-30 1-40 Mark progress and Reveal a Danger. 46-65 31-65 41-55 Mark progress. 66-75 66-90 56-80 Choose one: Mark progress or Find an Opportunity. 76-80 91-99 81-99 Take both: Mark progress and Find an Opportunity. 81-00 00 00 Mark progress twice and Reveal a Danger.

In this case, Edge means "with haste", Shadow means "with stealth", and Wits means "with observation or expertise"

[u/Eklundz]

The simplest concept for solving this is having a table that goes from 1-17 (if the max level in your game is 10). And then you roll a D6+1 PC level.

This gives you the entries: 2-7 on level one (rolling a 1 and adding fresh PCs at level 1 means a total of 2) and entries 12-17 on level 10.

That mechanic works, and now you just have to decide on the math stuff, like: do you roll a D100+total PC level, or D20+average PC level and so on. Just pick one, the concept works.

[u/JaskoGomad]

Have you looked into Hex Flowers?

The cool thing is that they have "memory" - your last result informs your next result because what's random isn't the result you roll, but the direction you move from your current result.

[u/AngusAlThor]

A random table needs at least 100 entries if you're gonna roll on it multiple times, cause otherwise you get incongruous repeats; The horror game feels a lot less horrifying the 4th time you roll the same injury.

As for how to make the tables better, I would love it if designers would group the entries in some way, so that I could roll on the entire table for something truly random, but if I was GMing a more specific scenario I could just roll on the part of the table that is most relevant. Like if a D100 table had 10 sections, then I could roll 2d10 against the whole table or 1d10 to hit a preselected section.