Ask a stranger to picture Warhammer 40,000 and — whether they know the name or not — they will describe a Space Marine: a seven-foot armoured giant with shoulder pads like bin lids and a gun that fires rocket-propelled bolts. The Adeptus Astartes are the poster boys of the entire setting, the first miniatures most of us ever slapped paint on, and four decades in they are still the most collected army in the game by a country mile.

The new Space Marine hub on our site opens with a line that does a lot of heavy lifting: each Space Marine is a genetically re-engineered super-soldier — faster, stronger and utterly without fear, clad in ceramite power armour and armed with the finest wargear in the Imperium. Bold claim. Here is what it actually means, why these gene-forged demigods have ruled the 41st millennium since 1987, and how to muster a chapter of your own.

What exactly is a Space Marine?

Not a bloke in a big suit. A Space Marine begins life as an ordinary human boy — usually plucked from the most feral, brutal world the Imperium can find — and ends it as something else entirely. Each aspirant is implanted with nineteen additional organs grown from the gene-seed of one of the Emperor's primarchs, in a series of surgeries that takes years and kills most of the candidates who attempt it. The survivors come out the other side over seven feet tall, with two hearts, three lungs and a nervous system rewired for war.

And the biology is gloriously daft. Highlights include:

• Secondary heart: a spare, for when the first one takes a bolt round.
• Betcher's Gland: lets a Marine spit corrosive acid. Genuinely.
• Sus-an Membrane: suspended animation on demand — battle-brothers have been revived after centuries of apparent death.
• Catalepsean Node: rests one half of the brain at a time, so a Marine never truly sleeps.
• Black Carapace: a sheath beneath the skin that hard-wires him into his power armour, turning the suit into a second body rather than a uniform.

Stack hypno-indoctrination on top — decades of psycho-conditioning that scrubs out fear the way you would sand off an old paint job — then seal the whole lot inside ceramite power armour and hand it a boltgun that fires self-propelled explosive rounds. That is the baseline trooper. The Imperium has roughly a million of them, and it is still not enough.

One gene-line, a thousand flavours

Space Marines are organised into chapters of roughly a thousand warriors, each with its own colours, culture and glorious hang-ups. Picking a chapter is the single most enjoyable decision in the hobby, because it decides what your army looks like and how it plays:

• Ultramarines: the sensible blue ones — codex discipline, clean lines and the closest thing 40k has to main characters. Our Ultramarines army analysis covers them in depth.
• Blood Angels: gothic renaissance vampires who are exceptionally good at chainsword-based diplomacy. See the Blood Angels army analysis.
• Space Wolves: Vikings with knives, riding actual wolves. Browse the Space Wolves range and try to resist.
• White Scars: lightning-fast bikers who treat every battlefield like a motorway with no speed cameras.

And yes — some of them went spectacularly off the rails ten thousand years ago. Those ones now have spikes, grudges and their own Chaos Space Marines collection, but that is a story for another day.

Why they make a brilliant first army

Lore aside, there are thoroughly practical reasons the Adeptus Astartes are the most recommended starting point in Warhammer 40k:

• They are forgiving on the tabletop. Tough stats and a 3+ armour save mean one positioning mistake rarely deletes half your army — exactly what you want while learning.
• They do everything. Infantry, bikes, tanks, dreadnoughts, jump troops — every part of the game is on the menu, so you can find your play style without switching factions.
• They are easy to paint well. Big armour panels take base coats, washes and edge highlights beautifully. A tabletop-ready squad is achievable in your first week.
• They are the best-supported range in the game. More kits, more rules support and more painting guides than any other faction, full stop.

If you want the no-nonsense shopping list, our Space Marine core units collection gathers the workhorse kits every chapter uses, whatever colour you end up painting them.

How to start your own chapter

Step 1: Pick your chapter

• Choose with your eyes. You will paint this scheme fifty times, so pick the one that makes you want to open the box. There are no wrong answers — only Ultramarines players will tell you otherwise.

Step 2: Grab a starter set

• The current starter boxes are outrageous value and include Marines by default. Our guide to the 11th edition starter sets breaks down which box fits your budget.

Step 3: Add the core units

• A squad of Intercessors, a character to lead them and something big and stompy will carry you through your first dozen games.

Step 4: Paint the lads

• Base coat, wash, edge highlight — power armour makes you look better at painting than you actually are. Everything you need lives in our Warhammer Colour paint range.

Final Thought: every hobbyist remembers their first Space Marine — usually painted badly, always painted proudly. Forty years of new factions, new editions and shiny distractions later, the gene-forged demigods are still the beating twin hearts of Warhammer 40,000. Start there. Everyone does.

Further reading: new to the grim darkness? Start with Your First Steps into Warhammer 40,000, then get the brushes out with How to Paint Your First Warhammer Miniature.