2400 and 24XX: The What and Why

What: 2400

2400 by Jason Tocci is a collection of easy to play and run roleplaying games, each of which are condensed in an innovative 4-page format. Personally, I have run 2400 and its derivatives for a variety of people, including but not limited to a group of autistic kids as an exercise in speaking up and pitching ideas. As such, I am very confident in saying that 2400 is especially unique in its way of captivating any type of gamer (well, maybe except PF diehards). The skill resolution is intuitive and gets across exactly how the game works without blasting it in your face with tons of advice on how to play what is very open-ended in interpretation. On the other hand, the advice that is presented gets to the point and sets the tone excellently.
Did that STILL not sell you? Well…

Why: 24XX

An intuitive and innovative system such as 2400 is ripe for hacking, especially due to its tradition of being within 4 pages including cover. What sets it apart from other roleplaying games is how open it is to hacking. As far as I’m aware, the 24XX SRD is one of the first to include many different templates for formatting, including advice within and designer insights.
Even if you aren’t a big fan of the hard sci-fi genre, there is sure to be a hack that you WILL like. With over 100 hacks, and more constantly being churned out, you can rely on getting the same innovation of 2400 in a bite-sized format with a couple tweaks to fit the established world.

So, what are you waiting for? Tell us about your experience with 2400, what you think about it, questions, or more!


Also posted on rpg.net!


24XX is one of my favourite engines around. I have 3 hacks up for sale on itch. It’s immensely hackable and expandable. The layout was what sold me first. It uses the 4 pages extremely well, giving you a compact RPG including setting & adventure informed by random tables and not exposition. I still have a folder full of unfinished hacks around and follow new releases closely. It’s very good and my go to one shot game.

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What is a PF diehard? …specifically PF?

I have been looking at getting the main bundle from DriveThruRPG for sure!

I’m not the best at one-shots, do the mechanics quickly get boring for longer runs with the same characters? With minimal games I’m always a bit worried that you end up in the uncanny valley between just “lite” games that offer some mechanical variety and outright wing-it FKR where nothing gets in the way.

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Not at all, I played short 5 session campaigns with it. There is enough growth for quite some entertainment. It’s just for me personally I prefer a bit more crunch for long term games.


PF I assume is Pathfinder. I’d recommend getting the 2400 bundle on itch.io. Though 24XX has two or three games from the bundle for free.

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I think it really depends on what you and your players are looking for as sessions go on. If they are looking for some very set very explicit growth mechanics with milestones to hit to get more powerful or whatever then maybe/maybe not? But if you just want to do entirely diegectic progression then you can play as long as you want.

I am running a hack of it (1400 Below) and running some folks through Deep Carbon Observatory - we’ve played three sessions but based on their progress unless there are outside pressures to speed up I see at least nine more? Probably more?

Will there be any advancements along the way - yeah a handful - but I also doubt my players would feel cheated if they didn’t get advancements.


I’ve always kind of liked 2400. And the GM advice section (see below) common to each game is some of the tightest, best advice out there on running a game. But I also never really “got it”. Why are there so many of them? It’s the same mechanic, the same kind of character creation, with a few different tables.

But then Tocci started writing his devlogs/postmortem series over on pretendo games and it was a real eye opener. I would never otherwise have realized the nuance and the thought that went into each game.

Now I have a dream of running a series of shared-universe games using each (most?) games in the core 2400 bundle.

GM: Describe characters in terms of behaviors, risks, and obstacles, not skill dice. Lead the group in setting lines not to cross in play. Fast-forward, pause, or rewind/redo for pacing and safety; invite players to do likewise. Present problems you don’t know how to solve. Move spotlight to give all time to shine. Test luck as needed to check for (1– 2) an encounter or anomaly or (3–4) signs of one nearby. Improvise rulings to cover gaps in rules; revise unsatisfying rulings as a group.