LUMEN Review – An SRD For The Quick And Powerful

Sometimes you just want a game where the characters are just awesome. So powerful that death is just a speed bump, so badass that there’s almost nothing they can’t do if they play to their strengths, so deadly that enemies aren’t just opponents, they’re walking health and ammo packs. If this is sounding like a couple of video games you know, you’re not wrong, but this is still a tabletop roleplaying game article. Instead of talking about a singular game, though, today I’m looking at a system used to build them, the LUMEN SRD from Spencer Campbell!

Just in case you’re new to the idea, a System(s) Reference Document is a toolkit for designing a new game using an existing system. They typically lay out the ground rules for what makes a game designed for System X a System X game in the first place, providing a foundation that other designers can then build off of to create new games and game material.

Campbell makes it clear, however, that this SRD is not going to read like a technical manual. Likes and dislikes about games and game design are going to be discussed, design decisions are going to be broken down, opinions are going to be made clear. For me, this honestly makes reading an SRD a more pleasant experience – instead of ‘do this’, it’s always better to hear ‘here’s why do this’.

Core Mechanic

The basic bones of LUMEN are very simple, consisting of d6 dice pools with ranges of success; you’re rolling X number of d6s, keeping the highest result, and that result tells you how well you did. 1-2 is a failure with a consequence, 3-4 is a success with a complication, and 5-6 is a success with no problems. Nothing flashy at this point of the SRD, no Forged-in-the-Dark-style critical success or anything like that, nothing revolutionary (and that last bit is Campbell’s statement, not mine). The learning curve on this one is a flat line. Things start to get a little more interesting when we look at where those d6s come from.

LUMEN games aren’t going to have any kind of skill list, says the SRD, because the characters are supposed to be “highly qualified and capable badasses”. They’re good at what they do, goes the theory, so we don’t need to know how many points they have in lockpicking before they try and get through a locked door. How they go about doing something is what’s important, and if you’re familiar with Fate Accelerated and its Approaches you might be starting to nod along at home.

Each LUMEN character is going to have three Attributes. One is going to represent powerful actions like feats of strength and emotional situations. The second represents speedy actions, like having fast reflexes or coming up with the right idea quickly. The third attribute is for patient actions, for when you’re being methodical and applying exactly the right expertise.. Each LUMEN game should give these attributes a name that fit it; LIGHT has the “powerful Pyre, the lightning quick Volt, and the patient void of the Nether.” Handily, this section also provides some examples of what these Attributes can do from NOVA, from both in and out of combat. Force would brute force a console and spray a room full of lead. Flow would quickly hack the console and take aim mid-flip. Focus would carefully unlock the console and land carefully aimed shots.

Can’t figure out what Attribute fits your action? Maybe you don’t need to roll it . Campbell spends some words decrying Perception checks here: not badass, and so probably not worth the time.


Even considering Attributes, we’re still pretty light on details that will make a character function and pop, and their Class is where we’re going to get what we need. Campbell takes a moment here to talk about what inspired LUMEN, and it’s largely video games that themselves have unique classes. If LIGHT wasn’t a giveaway, Destiny’s Guardians get a nod as a fine example of LUMENesque characters with the Titan, Hunter, and Warlock classes and their unique powers. Overwatch characters are all shooting the place up but each has unique abilities. Diablo classes customize power sets so no two characters play the same. This led Campbell to design LUMEN characters with classes that have the aforementioned 3 Attributes, Health, a Resource, and 3-5 unique Powers.

LUMEN characters don’t really die particularly easily – Destiny’s Guardians can get splattered all day long and jump right back into the fight – so why are we worried about Health? Well, by Campbell’s logic LUMEN games are very much combat games, and if you don’t have a mechanic for taking punishment, what’s the point of the combat? Most bad guys are going to be dealing 1-2 harm whenever they land a hit, and a class is going to provide 5-10 health. You don’t want more than that because it slows down the pace of things if anyone is a big bag of hit points. A LUMEN game will probably have one or more death penalties that kick in instead of outright dying – it might change how you’re rolling the dice, it may remove access to Powers, or it may inflict narrative penalties. The lower the starting health of a class, the more often the penalties are going to be a problem. Final death isn’t on the table for a LUMEN game, unless you really want it to be.

A class is going to need a Resource of some kind. “Energy, fuel, ammo, whatever you want to call it”, and it’s a limited resource that you’ll have to manage. Primarily, your Resource du jour is going to be spent to activate Powers, but you might create other uses for it if you want – LIGHT’s, er, Light can be used to resurrect characters when they die, reroll Attribute rolls, and shrug off damage. The advice Campbell gives for designers who want to provide these extra uses is to make sure there’s a way to recover the Resource quickly, so players aren’t in danger of running out and are spooked into never spending it in the first place.


This is where you get to do the really exciting things, but . . . why only 3-5? “Speed.” A power fantasy game with a lot of fighting stops being fun if a single fight takes hours, posits Campbell. LUMEN characters should be wiping enemies out with their Powers within real-time minutes, and limiting the number of Powers available is to help avoid analysis paralysis and keep things moving.

A Power is defined simply as “something that [a] character activates during a fight to give them an edge”. They might resolve immediately, or they might persist for a time (interfering with enemies, boosting allies, etc.), They might all cost the same thing, typically 1 Resource, or they might have different costs so that some are truly incredible. The thing about fueling Powers with Resources is that you don’t have to roll any dice for them, they simply happen, leaning into the power fantasy side of the system.

There are some pretty straightforward examples from LIGHT, all of which follow the 1 Resource cost. Fire Forge  hurls fiery hammers to deal Harm to multiple targets and create pools of flame, while Bubble creates a barrier with 10 Health around you and your allies that attacks can’t pass through in either direction. Examples from FRAME showcase a little bit of how you can push the SRD, including having higher costs (Blade Storm targets as many enemies as the points of Energy that you spend), passive Powers that improve certain types of damage and don’t cost a Resource at all, and Powers that can be improved.

The Powers section ends with Campbell talking about ways you might push the envelope or customize things a bit, including things like the passive perks, health alternatives, genre specific stuff . . . including advice on what not to do, specifically not adding too much stuff so you don’t clog up the works.

Character Creation Options

In building the character creation section of your LUMEN game, you’ll broadly have two choices. Your classes can come prepackaged with their Health, Resources, and Powers already locked in, or they can be made a la carte where the Class has Health and Resources and the Player picks Powers from a list. Neither is better than the other from an objective standpoint, they just do different things. Prepackaged means you can build a smaller number of thematic classes, which results in being a little hemmed in I suppose but really decreases the Powers learning curve. A la carte is going to make every character really unique, at the cost of taking a little longer to make them and an imperative on the designer to make a much longer list of Powers that are “equally enticing, otherwise you’ll see all  your players choosing the same small set of Powers.”


A Battle in a LUMEN game is described as ‘tactical-lite’ – you’ve got rounds and turns because Campbell believes more narrative action flows aren’t as intuitive to combat and because Powers and weapons are often linked to definable periods of time, but there’s no initiative tracker or anything like that built in. Basically, each player gets a turn, then the GM gets a turn at the end, and then it’s a new round.

A player character can move freely – no map required, ranges are abstract and we’re taking snapshots of characters being awesome not tracking movement – and take one action per turn. Attacking is, of course, going to be the usual offering. Here’s the trick, though: a Power is not an action, so you can blaze away with a pistol and drop a Gravity Bomb in the same turn: “Powers are the opportunity for the players to show off, and sometimes being able to string together a weapon attack alongside a power feels very cool.” Campbell does remind the reader that this is only the default, however. It definitely blows the “action economy” out of the water, and that’s the point, but a designer will have to decided if that fits the style of the game they’re trying to create.

Anyway, the GM isn’t sitting around twiddling their thumbs for 3-5 turns until theirs comes up, because any time a player’s result is a 1-4 there’s a complication or a consequence that lets the GM use the enemy forces. When the GM’s turn actually comes up, they do two unique things: Change the Battle in a big way, and Generate Drops. Changing the battle keeps the fight from just being a case of mowing down waves of boring zerglings – it’s reinforcements, different tactics, new enemy types that are resistant to the PCs’ approaches so far, a change to the environment, or more. The Drops are where LUMEN’s looter shooter DNA starts to shows up – the GM rolls 1d6 for every enemy that perished in the round, generating Health, ammo, Resources, etc. The d6 determines what kind of Drop comes from a given enemy, and the game you’re designing will determine what Drops are available and how frequently they appear; NOVA goes 50/50 for Health and Energy, but a game that wants scarier damage might have Health only show up a third of the time.


Get a load of this lot. They’ve got Health the same as a PC, although probably not as much and more than 10 is almost certainly too much. They can deal Harm, which usually has at least some range tags so you know where the need to be in order to be effective. And they have three moves. That’s basically it.

A consequence or complication can always be used to ‘activate’ an enemy on a player’s turn, usually dealing Harm and using a Move when appropriate. When it’s the GM turn, in addition to Change the Battle and Generate Drops, they can also activate a bunch of enemies at once to really shake things up. Exactly how many isn’t defined here, and it’s recommended that you codify exactly how this works for your game; an example provided is to activate three enemy Moves.

As for the Moves themselves, they “represent the tactics they use, the types of actions and reactions most commonly seen in combat, or just generally their disposition on the battlefield.” If you’ve guessed the reason that they only have three Moves is to make the GM’s decision on which to use quick and easy you’ve been paying attention. An example enemy provided in the SRD, Loyal Foot Soldiers, have Duck behind cover for a moment, Summon an arcane turret, and Obey Commands as their Moves.

The section ends with a bit of snark. “How are they used? Great question.” The implication would seem to be that the Moves you give enemies are going to be highly dependent on the LUMEN game, genre, and setting you’re creating, so it’s up to you to decide how you want them to work.


Aside from the no doubt widespread havoc you’ll be wreaking with your Powers, LUMEN characters are going to need Weapons to determine the results of their Attribute rolls while on the attack. What types of weapon are available depends on your setting – LIGHT is all about gunplay, while NOVA mixes firearms and melee weapons. All weapons will have at least three things: a name, how much Harm they do by default, and a Range that defines where the weapon works. To make them really interesting, though, you’ll want some tags.

LIGHT provides our examples this time. A weapon with Burst deals an additional Harm when you roll a 6. One with Elemental is effective against shields. Another with Fount will give the character +1 Light after getting a kill. Campbell advises making a long list, with most of them being mechanical in nature but some being purely narrative for fun. By default LUMEN games are going to randomly generate weapons, with 1 to 2 tags, although there are exceptions we’ll get to later.

Basically, when using a weapon in combat, it inflicts the Harm so long as you succeed (roll a 3+) on your attack, and then you see if any of the tags are relevant and activate as needed. Easy enough!

Gameplay Loop

This is where Campbell talks about what characters are actually going to be going out and doing. “I LOVE solid gameplay loops,” it is said, and Blades in the Dark‘s “You go out on your heist, do the job, then come back and downtime” is highlighted. As a result, LUMEN games are built around missions. Whether it’s clearing the dungeon, launching the mechs into combat, or an actual heist, the PCs “need to go out and accomplish their mission, and look good doing it.”

Here’s the LUMEN loop: a short briefing where the PCs get their mission, the lion’s share of time is then spent actually on the mission, and the characters advance after the mission is complete. Extremely straightforward.

A lot of the rest of this section is pure advice and discussion, because a lot of it are going to be decision points for the designer. How do you generate missions? Tables are highlighted as one method. What does the briefing (and potentially debriefing) look like? Characters will roleplay in battle, sure, but you won’t get a lot of chances to just talk with people when on a strike mission. How long these windows of roleplaying will be and what they entail will be up to you.

Adding to the loop is also discussed – factions would help you decide who’s giving the characters missions, let the PCs build up reputations with other factions, and provide chances for players to buy in to the setting as they pick which to work with and which to fight. Mission structure is another point with some wiggle room; Band of Blades gets a shout out here, with its usual method of presenting three missions that the players have to pick between. Also, “adding stakes to the mission helps give weight to the game.” Basically, since death isn’t really a problem, there should be something else at stake for the characters to be worrying about.


So, you’re advancing after every mission. There’s two broad avenues to do so: character advancement, and loot advancement.

Character advancement might increase an Attribute, Health, or the Resource for a start. You might also use Powers as a route for advancement – NOVA has Powers with advances to improve the base power, like increasing the Harm dealt or the duration of the effects, or providing a new way to use the Power. You might also let characters gain new Powers, although there’s a pointed reminder to not have more than five. You might have players replace existing powers with the new ones, or perhaps let them have a larger list but have them ‘equip’ 3-5 when going out on a mission.

Not every LUMEN game needs to have a particularly robust item system, says Campbell, but for those that do advancement is where the looter shooter DNA really shows up. Loot advancement could see new weapons getting generated at the end of every mission, the characters gaining favor with weapon makers to gain access to new weapons, adding or swapping out tags, or gaining access to legendary weapons.

Of course, as mentioned at the start everything that I’ve talked about is not actually a game that can stand on its own – this us a System Reference Document for designing games, and an SRD is only as healthy as the ecosystem of games that end up using it. The restrictions on making a game are pretty light – you’re simply asked to add a logo and a small blurb giving credit to your work, that’s it. So what’s been “Illuminated by LUMEN” so far? Lucky me, Campbell spared me some searching by providing a series of fine and elegantly crafted links.

There’s the obviously-Destiny-inspired first game created with the system: LIGHT.

Campbell is also currently Kickstarting a LUMEN game, NOVA! It’s an action-packed mech game set in a world where the sun has exploded. The Kickstarter has surpassed its funding goal as of this writing and goes until July 3rd.

You can find an ongoing list of published LUMEN games with this collection Campbell put together!

There is also a LUMEN Jam happening on itch – it runs until July 7th for most timezones, and as I look at it while I write this it already has 24 submissions.

Finally, there is the Lux Collective, which is a gathering point for LUMEN games that are currently giving itchfunding a go. The problem with itchfunding, like a long of things with, is the interface – finding them is very difficult. Itchfunding doesn’t even have a tag of its own (Aaron told me this and I had to go check, because I couldn’t believe it), so a prospective supporter is forced to relay on third party sites like, well, CHG or this handy little list that Kegan puts together. Campbell making a dedicated effort to help LUMEN games along with their itchfunding is a particularly clever move.

Combat in roleplaying games is, particularly in traditional games, where the rules get the most complicated. I have a friend who describes the transition from narrative time to combat time in D&D as ‘a wall coming down’ (thanks Dan!), and it’s a perfectly applicable way to describe many other different games. Things are often fast and loose until weapons get drawn, and then all the abilities and rules and exceptions and square-counting and initiative tracking and so on come into play and slow things down.

LUMEN, paradoxically, is a combat-heavy system that goes rules-lite and manages to make it work.

Other systems that devote the same percentage of page space to combat as LUMEN does tend to get bogged down in little unique rules and mired in subsystems. In  contrast LUMEN gives you everything you need to design a game of powerful, badass combatants – no page flipping required.

You can find Campbell on Twitter,  join the Gila RPGs discord server, and can grab LUMEN yourself for the always delightful price of Pay What You Want (with a recommended price of $2.00 if you like what you see),

Check LUMEN out, and bring a little light to your next game design project!

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