Every day of Advent in 2024, Games Workshop surprised Warhammer 40,000 players by releasing new detachment rules for every possible army, and everybody loved it. Then, just a few days ago, Games Workshop revealed 3 more detachments, completely out of the blue, and everybody loved it. The reason a detachment is so exciting is because it lets you take an existing army (the one you've spent hours building and painting) but apply brand new special rules to it. It's an optional expansion set for your core game, and there's literally no down side to it. The reason this works so well is because the 10th edition of Warhammer 40,000 was designed for modularity and is now reaping the benefits.
In the 10th edition of Warhammer 40,000, every miniature (and most or all weapons) gets at least 1 keyword. The keyword usually specifies what in-world faction the miniature belongs to, but it might also identify what role the miniature plays within that faction, or some other notable attribute.
Because every miniature in an army has a keyword, game designers can define what assortment of keywords constitutes a legal army, and also what special abilities each keyword confers. This is the detachment, and you see it used in:
That's not 2 or 3, but 4 distinct products for Games Workshop, all from just one simple design choice. Make it modular, and you can assemble and re-assemble rules like they're Lego bricks.
Modularity isn't a buzzword, it's a real thing that solves problems. For the 10th edition of Warhammer 40,000, modularity allows game designers to arbitrarily define parameters by adjusting a variable by its keywords.
Here's a simple and fictional example. Suppose there's a faction called Chunky Soldiers in your game. There are 2 types of models in this faction: Tanks that hit hard but die relatively easily, and Shields that take a lot of hits but don't have the best weaponry.
You want to design an offensive army detachment that hits hard. I mean really hard, like the hardest of hits possible. If you just grant the Chunky Soldier faction lots of hit bonuses, then obviously the correct strategy for a player is to fill an army with Shields so that this hard-hitting army can also endure lots of damage. It'll be undefeatable, and not fun for whatever unlucky player is playing opposite. To solve that problem, you specify that this detachment consists of no more than 1 Shield unit for every 2 Tanks units.
Switch that restriction around to create a detachment that endures lots of damage while dealing small amounts of damage every round.
You can take it even further, though:
One of the most important elements of a modern tabletop game is how the mechanics reflect the lore. It's certainly true that games don't require lore. For most of human history, tabletop games were primarily about numbers and rules. Nobody ever came up with names and backstories to the king and queen in a deck of cards. Nobody wrote a series of novels, one for each of the pawns in a chess set. But in modern games, a lot of players expect to be playing in a fictional world, and to be themselves telling a story out of a larger body of work. Significantly, breaches of the internal logic of a game world can interefere with how players feel about a game.
You might suspect a detachment that grants new rules to 40k miniatures would introduce inconsistencies to a firmly established Warhammer universe. Why do my Skitarii Rangers get to claim objectives they walk away from in one detachment, but not in another? How can the same unit of space marines be really fast but vulnerable to psychic attacks when I use one detachment, and really slow but resistant to psychic attacks when I use a different detachment?
It turns out that the rules writers are careful to explain the concept behind a detachment. That's often enough to explain why an army acts one way today and a different way tomorrow. Maybe the army has a new commanding officer, maybe they have special orders, maybe they're trying out new technology, new strategies, or adapting to a new environment. There are lots of different reasons for why your army might gain abilities for one battle and lose those in favour of something different in another battle, and thanks to nice flavour text for stratagem names and special rules titles, you can invent all the justification you need without too much effort.
Traditional wargames are often seen as variations of chess. Each miniature has a role, but the effectiveness of each miniature is determined by a dice roll.
I think modern wargame design share more in common with trading card games. You've got a deck of cards, and each one breaks an established rule in some interesting way. The scope of each card is defined by a model on the tabletop.
On the one hand, it means that as a player you might have a lot of new rules to keep in mind with each game. Trying a new detachment isn't necessarily trivial. You have to learn the detachment's rules well enough to at least remember when to check for triggers. On the other hand, your army is flexible and offers you a variety of play styles. Find the one you like, and play it until you yearn for something different. That flexibility is provided by good modular design, and I hope Warhammer 40,000 leans into this all the more in the near future. You don't need an 11th edition when you have modularity.
Photo by Ryoji Iwata on Unsplash