WRITTEN BY
Bill Heron & Justin Alexander

This is the book that lead to me becoming the co-creator of the Infinity roleplaying game. And now, by a very long and very strange road, you can finally add it your own collection!

Back in 2015 I was shopping around for a publisher who would let me develop and publish a node-based campaign. I eventually reached out to Modiphius, spoke with Chris Birch (who owns the company), and was assigned to the Mutant Chronicles RPG. I started reading the existing material for Mutant Chronicles, but a few weeks later, Chris reached out and said, “Actually, we’ve got this new RPG we’re developing called Infinity, based on Corvus Belli’s tabletop miniatures game. We need a really cool campaign for it, would you like to work on that instead?”

When I took a peek at the Infinity universe, I loved what I saw, so I jumped at the opportunity.

Over the next couple months I started developing the material for, first, Acheron Cascade and also a second campaign. I’m not entirely clear on the sequence of events here, but by the summer of 2015 Infinity no longer has a Lead Developer. At Gen Con that year, I had a few meetings with Chris Birch and others about the campaigns I was working and these evolved into a broader discussion of how I thought the Infinity product line should be organized.

If I recall correctly, on Sunday, as I was packing up my suitcase to head home, I got a call from Chris offering me the job as Infinity‘s new Lead Developer. Which was simply amazing.

Within days we were launching a Kickstarter that was revamped to match the blueprint for the product line I’d proposed, and we went on to have the largest Kickstarter ever for a first edition RPG. (This record has since been blown out of the water multiple times over.)

But now that I was focused on developing the core game, Acheron Cascade needed to be laid aside for a bit.

It got laid aside for a long time.

I eventually left Modiphius, in part because I really wanted to focus on my campaign. I spent a few months fleshing out the first few adventures and beginning to playtest them, but, ironically, I wasn’t able to finish the campaign because a few months later I was hired by Atlas Games to become their RPG Developer.

Benn Graybeaton, who had taken over for me as the Line Developer for Infinity, brought in Bill Heron. I was able to pass my development notes and playtest drafts over to him, and he managed to somehow turn them into a finished book. Bill’s a hero and I’m so grateful to him for using what I’d begun and bringing a book that I thought I would never see to life.

Hope you enjoy it!

INFINITY – ACHERON CASCADE
Modiphius Entertainment – 2022
(Co-Author)
Print Edition – PDF Edition

Momentum in 2d20 is generated when you roll more successes on an action test than required by the difficulty of the check. These points of Momentum can be spent to either immediately improve the result of the current check or saved to be used in the future, allowing you to build Momentum over the course of several lesser actions until you can accomplish big things.

Momentum can be spent to do stuff like:

• Add +1d20 to future skill tests
• Create obstacles for opponents (generally increasing the difficulty of their skill tests)
• Improve the quality of success
• Increase the scope of success
• Reduce the time required to accomplish a task
• Perform a normally noisy action stealthily
• Take an extra action in an action scene
• Boost damage on an attack
• Get a called shot
• Trigger program effects in Infowar

And so forth.

In Infinity we also specifically emphasized that Momentum is best seen as a creative tool for empowering the players. The GM is also given several structures for making complex rulings around Momentum (see p. 407 of the core rulebook).

One of these is using Momentum to model preparation. If the PCs want to take one action to set up or create advantage on another, the GM can call for a test on the first action (even if it normally wouldn’t require an action test) and then any Momentum generated on that test represents the advantage gained on the primary task.

One of the limitations to this approach, however, is that Momentum ablates over time. At the end of each scene, the team’s pool of saved Momentum is decreased by one. This means that if you want to set up an advantage in one scene that will benefit you for the next scene, it’s difficult to do that.

This problem can be solved by adapting a cool mechanic from Trail of Cthulhu: dedicated pools.

DEDICATED MOMENTUM POOLS

A dedicated Momentum pool can only be used in a given circumstance or in relation to a given subject. For example, you might hack the security cameras in a megacorp’s headquarters, creating a pool of Momentum that can be spent on things like Stealth and Observation tests when the PCs go to infiltrate the HQ.

GMs might also rule that certain resources simply grant a pool of dedicated Momentum. (Perhaps the patron who hired the PCs to steal the megacorp’s new research into captured Tohaa technology simply hands them the access codes to the security cameras as part of their briefing packet. They get the same dedicated Momentum pool even though they didn’t make any skill tests to obtain it.)

There are two advantages to a dedicated Momentum pool.

First, the dedicated Momentum pool does not ablate. The dedicated Momentum pool is separate from other saved Momentum and does not decrease at the end of each scene. This makes a dedicated Momentum pool a great model for preparations that play out over multiple scenes or which are made long before their intended use: The PCs lose some of the utility of the Momentum (since it has to be used for a specific purpose), but in exchange the Momentum becomes more durable.

Second, the dedicated Momentum pool can also create unique vectors that allow the PCs to take actions that they otherwise couldn’t. If you have access to the security feeds, for example, you can check them for activity in other areas of the building. If you have a copy of the religious text of an extremist Morat cult, you can reference it for information about their rituals that you would otherwise have no way of knowing.

These vectors can cut both ways, though! When the Momentum from the security camera pool runs out for example, it could easily justify the GM spending Heat to generate a complication in the form of the megacorp’s hackers realizing their system has been compromised and launching an Infowar attack on the PCs.

On page 33 of the Infinity roleplaying game, there is an “Advanced Rule” in a box:

As an advanced rule, instead of using a group pool for saved Momentum each PC can save Momentum and use it later individually. Players who have saved Momentum can spend it at any time to assist the actions of other player characters (or NPC allies) and otherwise influence the scene. At any given time, a player can save a maximum of six Momentum. In addition, any single action can benefit from a maximum of six saved Momentum. (For example, if two players had both saved four Momentum each, they still wouldn’t be able to spend all eight Momentum on a single action.) During Momentum depletion, each character loses 1 Momentum.

This is presented as an optional rule, but the truth is that, in my opinion and based on countless hours of playtesting, it is the only way that people should be playing the 2d20 System.

Let’s back up for a second and talk about how Momentum works in the 2d20 System, which was created by Jay Little for Mutant Chronicles and then also used in Infinity, Conan, John Carter of Mars, and Star Trek Adventures. When you resolve an action test in 2d20, you determine a target number based on Attribute + Skill and then you roll a pool of d20 dice — generally starting with 2d20, but expandable to 3d20, 4d20, 5d20, etc. You generate one success per die that rolls under the target number, plus an additional success if the roll is under the pertinent skill’s Focus. (So even if you’re only rolling 2d20, you’re often capable of generating up to four successes.) You succeed on the check if you score a number of successes equal to the difficulty of the task — so if the difficulty is 2, you need to generate two successes to succeed.

Here’s the final wrinkle: If you score MORE successes than you need to succeed at the task, those extra successes are converted into Momentum, which can be spent to enhance the current action or saved and spent later to gain bonuses to future checks, create obstacles for opponents, and other special effects.

At first glance, this seems fairly unremarkable. But in actual practice, it’s a really interesting system to GM for. As I wrote in the GM advice section of Infinity:

…setting a precise difficulty level is not a significant feature of the game. In fact, at least 95% of the time you will basically be deciding whether a task is of Average (D1) difficulty or Challenging (D2) difficulty. (The higher difficulty ratings of Daunting, Dire, and Epic obviously exist, but can be incredibly difficult or even impossible for some characters to achieve under normal circumstances. As such, they should be rare in their application.)

The reason for this is because the Infinity system is far less interested in the simple binary of passing or failing a check, and is instead intensely interested in the quality of your success, which is measured and leveraged through the use of Momentum.

So whereas a GM running D&D or Numenera or Feng Shui 2 is often giving a lot of thought to what the specific numerical value of difficulty for a particular test should be, the GM of a 2d20 game is instead generally just asking, “Is this check unusually hard?” If yes, then difficulty 2. If no, then difficulty 1. The mechanical focus of the game is (or, at least, should be) all in how Momentum is used after the check.

GROUP vs. INDIVIDUAL MOMENTUM

This brings us to saving Momentum. As noted, any Momentum generated by a check that isn’t immediately spent can instead be saved to be used in the future. The mechanical difference we’re talking about is whether you:

• put your saved Momentum into a group pool, from which any player can pull Momentum to spend; or
• put your saved Momentum into a personal pool which you control

The distinction between these points has little or no impact on game balance. Personal pools can theoretically allow a group to save more total Momentum, but in practice this rarely happens, it’s counterbalanced by the fact that every pool ablates a point of Momentum at the end of each scene (so the group loses saved Momentum faster), and the amount of saved Momentum that can be spent on a single check is capped at the same amount.

(We also playtested a variant which was completely equivalent mechanically: Total saved Momentum in the group is capped at 6 and the group collectively chooses which saved Momentum is lost during scene ablation. This makes bookkeeping more complicated and also tends to result in a pointless little “Momentum dance” where players spend their saved Momentum in order to open up cap space for the current player to save their Momentum.)

So if it’s basically mathematically equivalent, what’s the big deal?

Primarily, off-turn player engagement.

Consider a typical combat system: Everybody rolls an initiative and, when their initiative comes around, they take their turn. What happens when it’s not their turn? They just wait for it to be their turn again. The longer the wait, the more likely it is that they will become bored or tune out.

You can counteract this by giving players off-turn engagement. I discuss one example of this in The Design History of Saving Throws: D&D saving throws mechanically engage a player (i.e., let them roll dice) when it is not their turn. It’s a very basic form of engagement and doesn’t involve player agency, but it is physically engaging and that’s enough to break up the routine “it’s not my turn” cycle of tuning out.

When you used a group pool of saved Momentum that anyone can pull from, the player generating that Momentum gives up ownership of it. The only player engaged when the Momentum is used is the active player who is choosing to pull from the pool.

But if you use personal pools, then the player who controls the saved Momentum has off-turn engagement when they spend it to help the active player. This is off-turn engagement with the dial turned all the way up, because even when they’re not actively spending Momentum, the player is constantly looking for the opportunity to do so.

The other factor here is ownership. When a player dumps Momentum into a group pool it is almost immediately anonymized. When that Momentum is later spent by another player, the original player doesn’t feel any ownership over that; they don’t feel the direct connection between the thing that they did and the thing that the current player is doing. When Momentum is spent from a personal pool, on the other hand, the player has immediate and visceral agency. This usually also bleeds into the game world, with the player spending the Momentum explaining how their character is actually contributing to the current action.

This sense of collective contribution to success creates a group camaraderie that, once again, tends to transcend the specific moments in which Momentum is spent: The group is mechanically encouraged to view their successes collectively and take action collaboratively instead of focusing on individual accomplishments.

DESIGN HISTORY

So if I feel this strongly about personal pools being the correct approach for Infinity, why is it pushed off into an optional sidebar?

That’s a complicated question.

When I first became the Lead Developer for the Infinity RPG, the only 2d20 game in print was Mutant Chronicles. I was handed a mechanically complete lifepath system (that needed setting content slotted into it, but should otherwise not be touched) and a half-finished system that needed to be finished. So I spent a couple of months doing that and then turned my attention to developing the setting material for the core rulebook and the scenarios for Adventures in the Human Sphere, Quantronic Heat, and other supplements.

It was at this point, however, that the development process hit several problems. Basically, right around the time that I was declaring Infinity to be “system locked” (like picture lock for a film, I think of system lock as being the point where the mechanics are nailed down to the point where you can confidently develop supplementary material) there was a simultaneous project inside Modiphius to develop an internal 2d20 SRD that would create consistency between all published versions of the game.

In developing the Infinity version of the 2d20 System there were a couple key design principles I had established.

First, because we were going to be developing full-fledged systems for Warfare, Infowar, and Psywar, I felt it was important to streamline and simplify the core of the system. The complexity of the game would come from having these robust scenario/game structures, and therefore other sources of complexity in the system should be smoothed out.

Second, the 2d20 System in Mutant Chronicles — like the pre-Genesys system Little had designed before it — features a set of core mechanics designed to empower players and give GMs tools for making powerful, robust rulings, but then surrounds those mechanics with a ton of mechanically crunchy specificity. The core mechanics of the Momentum system, for example, are beautifully designed to empower player creativity and improvisation, but then the system works relentlessly to lock that down by providing a laundry list of specifically defined ways that you’re allowed to spend the Momentum. My own design predilections, on the other hand, lean the other way: Ditch all the hand-holding and just leave the powerful core structures.

These two principles worked well with each other: Focusing on cruft-free core structures simultaneously simplified the mechanical core so that it could be developed through the new functionality of Infowar and Psywar rather than a lot of situational rules.

But the principles didn’t work well with the new guiding principle of unifying all 2d20 System design to match the new SRD. The result was a tug of war for the heart and identity of the game, complicated immensely because we had a dozen freelancers working on supplemental material that had to be constantly revised every time the core mechanics were violently yanked in a new direction.

I won some of those battles. I lost others. In the end, the only way I could keep the personal Momentum pools that I felt so passionately about in the game was as an optional rule, and even that was a fight.

But, seriously, if you’re running a 2d20 game — any 2d20 game! — swap to personal Momentum pools.

Buy!

The Infinity universe is a glorious science fiction kitchen sink. A panoply of unique cultures and cool technology is all smashed together, and opportunities for adventure and excitement explode out of every interaction.

I’ve found that the incredible richness of this setting, however, can pose a unique challenge: When you’ve got Chinese and Korean and Arabic and Germanic and Scottish and Russian and Malaysian cultures all splayed out across a dozen alien worlds, it can create a real strain on even the most well-developed cultural literacy. And the leading edge of this challenge, at least for me, are the names: When the PCs seek contact with a new NPC and I’m put on the spot to create a name on the fly, that’s when the rubber hits the road. Years of practice with improvisation have given me a lot of confidence when it comes to Western European and/or flat-out fantasy names, but when a scenario calls on the distinction between Chinese, Japanese, and Korean cultures in the riven enclaves of Shentang, I just don’t have enough depth.

There’s only so many times the players run into Jing Li before it becomes a problem.

So I put a little elbow grease into it and created a tool that I think you might find helpful, too: A grand list of NPC names for Infinity.

GENERAL NOTES

Basic Use: Pick a name.

For Variety: Mix-and-match first and last names. (For example, take “Shing Bao” and “Tong Jun”. You can name a character “Shing Jun” instead.)

Disclaimer: Anywhere I’ve butchered local naming conventions, you can assume that it was a totally deliberate decision representing cultural drift over the next two hundred years. (Innocent whistling.)

ARIADNA NAMES

These have been split into four separate lists, one for each of the major cultures/political units on Dawn. All names are pulled from the appropriate cultural background.

• Rodina Gendered Surnames: The Western-style last names shown in the name list are gendered. Remove the –a suffix when using female last names for male characters (and vice versa).

NOMAD NAMES

Nomads are a chaotic mish-mash of disparate people. The list here includes Italian, German, Romanian, and Lithuanian names, mostly as a selection of names not found on other lists.

Nomad characters will also commonly pull from the USAriadna and Rodina (i.e., Russian) lists. Yu Jing and PanOceanian names are also not unusual. Mixing first and last names across multiple lists is encouraged.

PANOCEANIA NAMES

The PanOceanian name list is drawn from Brazil, Chile, the Philippines, Malaysia, and India.

Each name is culturally distinct (insofar as that distinction exists in the real world), but mixing-and-matching is consistent with PanOceania’s neo-melting pot (so don’t worry about crossing the streams).

PanOceanian characters could also use the Caledonian and USAriadnan lists (usually representing an Australian background).

YU JING NAMES

Mandarin, Korean, and Japanese names are Last-First. (Keep this in mind for characters who are related.)

Vietnamese names are Last-Middle-First. First and middle names can be freely interchanged when mixing and matching, however, so you’ve got a lot more options here than it might look like at first.

HAQQISLAM NAMES

Even in the real world, Islamic names are a pan-cultural mixture of local tradition, bureaucratic decree, and linguistic exchange. Haqqislam is an even more thoroughly mixed Islamic melting pot plus all the disruption entailed in a planetary exodus and colonization. In addition, the following notes are simplistic in the extreme. Basically: Feel free to mix-and-match with these names as much as any other.

Al Medinat Caliphate names are Arabic.

• Nasab: Arabic names often feature a sequence of patronymic names tracing an individual’s lineage; ibn meaning “son of” and bint meaning “daughter of”. (For example, Laila bint Miraj ibn Iqbal.) In the Human Sphere, it’s become more common to see matronymic bints rather than defaulting to the male line. (For example, Kinnia bint Jandira bint Adriana.)
• Surnames: Arabic surnames follow a dizzying array of cultural traditions. Historically, it wasn’t unusual for Arabs not to have any surname. (A practice which hiraeth culture brought back into fashion.) Honorific laqab are also possible, but beyond the scope of this cheat sheet. Nisbah surnames indicate where the individual comes from (or is associated with), and in some cases end up being an inherited surname instead. For this cheat sheet, roughly half of the Arabic surnames are nisbah for Bouraki locations. (You can kludge your own by looking at the map of Bourak and, generally, just adding “Al-“ at the beginning and an “i” at the end.)

Funduq Sultanate names are Turkish.

• Surnames: Used In a purely Western style (although often have an Arabic derivation, so stealing from the Arabic list can work well).

Gabqar Khanate names are Afghani and Kyrgyz. (Each listed name is culturally distinct.)

• In Gabqar, naming traditions have blurred, so you can freely mix-and-match the Afghani and Kyrgyz naming practices described below.
• Subordinate Names: Afghani MALE names often have two parts, with one usually a subordinate name. These subordinate names can appear first or second, but the other half is always the character’s “proper name” regardless of position. (You can create these by using the sample list of subordinate names or by mixing-and-matching from the list).
• Sample Subordinate Names: Mohammed, Abdul, Gholam, Ali, Khan, Jan, Shah, Din, or attaching the suffix –ullah to the other name (e.g., Kanatullah).
• Gendered Surnames: The Western-style last names shown in the name list are gendered. Remove the –a suffix when using female last names for male characters (and vice versa).
• Patronymic Surnames: Kyrgyz alternatively uses a more traditional patronymic surname. These are –kyzy (son of) and –uulu (daughter of) and can be constructed by combining them with any first name (e.g. “Ensar” becomes “Ensarkyzy”).

Iran Zhat al Amat Shahnate names are Persian/Iranian.

• Surnames: Although originally constructed similarly to Arabic nisbah, Persian names are inherited in a Western style.

(click for PDF)

(click here for PDF)

Here we have another one of my system cheat sheets, this time for a game that I was Lead Developer for. Like my other cheat sheets, this one summarizes all the rules for the game — from basic action resolution to advanced combat options to the nuanced gear options of the Human Sphere. It’s a great way to get a grip on a new system and, of course, it also provides a valuable resource at the table for both the GM and the players. (For more information on the procedure I follow when prepping these cheat sheets, click here.)

Infinity is a game of epic science fiction, mixing together transplanetary empires, alien invasions, existential threats, cusping transhumanism, and rich historical allusion into a kitchen sink of thrilling science fiction. The Wilderness of Mirrors scenario meta-structure will create wildly memorable gaming experiences, while the triple battlefield of Warfare, Infowar, and Psywar is implemented using a set of unified core mechanics which strips away the mechanical complexity so often found in cyberpunk-inspired systems.

I’m more than a little biased, but I think you should check it out.

HOW I USE THEM

As I’ve described in the past, I keep a copy of the system cheat sheet behind my GM screen for quick reference and also provide copies for all of the players. Of course, I also keep at least one copy of the rulebook available, too. But my goal with the cheat sheets is to consolidate information and eliminate book look-ups: Finding something in a couple of pages is a much faster process than paging through hundreds of pages in the rulebook.

The organization of information onto each page of the cheat sheet should, hopefully, be fairly intuitive. The division of pages is mostly arbitrary.

PAGE 1: CORE MECHANICS. As a 2d20 game, the core mechanics of Infinity revolve around skill tests, but (perhaps even more importantly) the concept of Momentum & Heat. Infinity Points are also summarized here for easy reference.

PAGE 2: ACTION SCENES. This page summarizes the core mechanical chassis on which all Action Scenes in Infinity are built.

PAGE 3-6: TRIPLE BATTLEFIELD. These pages detail the rules for Warfare, Infowar, and Psywar.

PAGE 7: ACTION SCENE MOMENTUM & NPC PROGRAM TEMPLATES. These two things don’t really have anything to do with each other, but the Action Scene Momentum page had enough space left over that I could put the NPC Program Templates on it, and those are too useful not to have at your fingertips during play. (They provide a a couple dozen hacking devices that you can give NPCs, allowing you to quickly customize hackers without needing to build a custom deck list every time.)

PAGE 8-9: VEHICLES, STEALTH, BASIC INTERACTIONS. Wrap up of some additional rules that flesh out the core engine of the game.

PAGE 10-14: GEAR. Based on playtesting with these sheets, the gear section was significantly expanded. Like a lot of science fiction games, Infinity has a need to cover a lot of different types of gear. We’ve kept those systems as streamlined as possible, but there are still specialized rules that are pulled out here for easy reference. Of equal importance are the Qualities cheat sheets, which chew up a lot of space but are really useful to keeping things moving in actual play.

PAGE 15: ADVERSARIES. They key info for running NPCs. This wouldn’t take up so much room, but the specialized rules for Fireteams (which make running large engagements much easier) and the full list of common special abilities (included for reasons similar to the gear qualities based on actual playtesting with the sheets).

A SIMPLER SET

These cheat sheets are sufficiently expansive that it would be very time consuming to review them in their entirety. If you’re looking for a quick introduction to the system for new players, here’s what I recommend:

• Page 1: Core Mechanics. (You can skip the specific details of how you, as the GM, can spend Heat. But the players need to understand how to flexibly use Momentum.)
• Page 2-5: The Triple Battlefield. Covering Warfare, Infowar, and Psywar does carry a heavier load than systems that only handle one of them.
• Page 7: Action Scene Momentum. (Emphasize that these are examples. The 2d20 System is nice if you run it as a RAW-above-all bundle of crunch, but Infinity really sings when you embrace the system’s potential for player improvisation.)
• Page 10: Lifestyles & Acquisitions. (It’s not a bad idea to take a look at the Lifestyle descriptions in the core rulebook, starting on p. 388. It’s a fairly short section, but it really encapsulates what it feels like to live in the Human Sphere, and that perspective can be really useful for players trying to create and get into their character’s heads.)
• Page 14: Remotes. (You can skip most of the other gear rules and bring them in as they come up in play, but I think the pervasive domotics and ability to take action at a distance through a variety of remotes is something that players really need to grok about the setting.)

Of course, you’ll also want to do a quick introduction of the setting. This can prove challenging because there’s A LOT of stuff going on in the Human Sphere. Standard advice about focusing only on the stuff that’s immediately relevant to your first 2-3 scenarios still applies here. But take a specific look at the “Human Sphere” sidebar on p. 8 (specifically designed to introduce all the planets) and the “Factions of the Future” sidebar on p. 27 (which introduces all the factions). Between those two, you’ll get a pretty good overview for the setting. The “Life in the Human Sphere” chapter (p. 140-145) is also something you might consider excerpting and giving to the players to read before your first session.

MAKING A GM SCREEN

These cheat sheets can also be used in conjunction with a modular, landscape-oriented GM screen (like the ones you can buy here or here).

Personally, I use a four-panel screen and use reverse-duplex printing in order to create sheets that I can tape together and “flip up” to reveal additional information behind them.