#novamarines

Yes, Space Marines do have "normal" clothes for everyday use.

They will often use their power armour for formal occasions since it's more impressive and intimidating — one of my favourite Gabriel Seth moments is in the short story Know Thyself by Andy Smillie when an Inquisitor pays the Flesh Tearers a surprise visit and Seth is literally not wearing pants:

Seth knelt in the Reclusiam’s centre, naked save for an ashen tunic that draped his broad frame.

Seth has to send two battle-brothers to distract the Inquisitor while he scrambles into his power armour to make a good first impression. 😂

However, as I have mentioned earlier, wearing power armour for extended periods of time creates an ungodly body odour. So when they're not in a combat AO, Astartes wear various types of formal, military, or casual clothes.

In general, Astartes are warrior-monks and will often wear monastic robes and habits (which can be quickly shed for a duel or close combat like Jedi in Star Wars:)

However, some Chapters also follow the fashions of their homeworld.

Here are some descriptions of Astartes clothes from the canon:

Ultramarines

Ultramarines are culturally inspired by Ancient Rome and often wear tunics or togas when performing administrative duties among mortals:

— Marneus Calgar.

Messinius was garbed in simple clothes: loose trousers, boots and a tunic that left his massive arms bare. He enjoyed the freedom of movement they gave him. So much of his life was spent enclosed in ceramite, he enjoyed being free of it.

— The Avenging Son.

They spoke in Guilliman’s library, his most sacred sanctum. Guilliman had removed the Armour of Fate, though it physically pained him to do so. Like Maxim, he wore a tunic and trousers. The primarch’s clothes were ultra­marine blue to Maxim’s forest green, and unlike Maxim’s heavily embroidered garb, Guilliman wore no decoration besides the buckle stamped with the ultima that fastened his belt. As usual, he sat at his desk, working while he talked.

— Godblight.

However, Ultramarines also have more formal wear:

Sicarius left his former quarters a short while later. He had donned a gilt-edged red cloak and light carapace breastplate over his training fatigues.

Prabian wore fatigues and light training armour like Sicarius, but he also had a small combat shield strapped to his left arm and wore a sheathed gladius at his left hip. A soft blue cloak with a silver trim swished in his wake.

— Knights of Macragge.

War Hounds

We also get descriptions of formal wear from the Great Crusade era, specifically the War Hounds (early World Eaters):

He looked at Dreagher again. Like Khârn, the man was dressed in white, bands of blue glittering across the high-collared tunic, boots and gauntlets a dark ceremonial blue rather than functional shipboard grey. The Emperor's lightning-bolt emblem gleamed at his collar and shoulder. His dress matched Khârn's own: the formal garments with which the War Hounds symbolised they were about their most solemn business.

— After Desh'ea.

Dark Angels

Dark Angels embrace the ascetic warrior-monk aesthetic to a very high degree:

— Will of Iron.

Space Wolves

Like most Fenrisians, Space Wolves wear furs and deerskin leather clothes:

Arjac moved to the other side of the throne to Fenrir so that he could see the vid-feed from the frigate approaching the space hulk. Like the Lord of Fenris, he was not in his armour, but dressed in a hide tunic and leggings, his arms banded with leather totem cords hung with fangs and bones, his thick belt riveted with iron honour badges. His freshly shaved scalp shone with the speckled starlight from the display. He dragged his fingers through his thick, newly trimmed beard.

‘It’s your pack, you choose the marking,’ growled Ullr. He was out of his armour too, but unlike the grey robes of Gaius and his companions he wore hide breeches tied with thongs from ankle to knee and a fur-lined jerkin that left arms and chest exposed.

— The Wolftime.

Blood Angels

In Dante, Dante himself dresses casually in red and gold day robes while doing office work. In Devastation of Baal, Dante also asks the assembled representatives of the Blood Angels Successor Chapters to attend a meeting in their day robes:

Erwin looked around, his curiosity piqued by the diversity of men who staffed his brother Chapters. As a last symbol of peace (although Erwin thought it more to save space) Dante had ordered that they attend in their day robes. These were almost as varied as their wearers.

— Devastation of Baal.

Blood Drinkers

The Blood Drinkers' homeworld, San Guisiga, is described as a hot, volcanic planet criss-crossed with lava rivers. In addition, a mutation of the mucranoid geneseed organ causes the Blood Drinkers' skin glands to atrophy, giving them very dry, itchy skin. As a result of the hot climate and skin irritation, the Blood Drinkers wear loose trousers and tend to go shirtless:

Chapter Master Caedis worked in his chambers. He was stripped to the waist; baggy, blood-red trousers on his lower half, soft black boots on his feet and a black tabard hanging between his legs – the manner of dress all Blood Drinkers affected when out of their battle-plate. The battle-barge was warm, the way the Blood Drinkers preferred; warm as the volcanic halls of San Guisiga, warm as blood.

— Death of Integrity.

Novamarines

The Novamarines, an Ultramarines Successor Chapter, lean more towards the battle-monks aesthetics:

Like him, he wore a bone-coloured habit, a deep-blue tabard hanging down the front displaying the Chapter badge: a skull surrounded by a stylised starburst. A silver sash embroidered with many campaign markings, the honours of a Deathwatch kill-team veteran, crossed the brother’s chest.

— Death of Integrity.

Entertainingly, in Death of Integrity, the Novamarines invite the Blood Drinkers to a formal dinner before embarking on a joint campaign and then fret among themselves about what to wear when welcoming the other Chapter, discussing the symbolic value of different attires. They finally decide on wearing their armour because they want to show the Blood Drinkers that the Novamarines are ready to follow the other Chapter into battle.

Iron Snakes

The Iron Snakes are heavily inspired by Ancient Greece, which also shows in their clothing:

Barefoot and dressed in a loose white chiton, Priad stood on the marble deck of the observation platform at the summit of the Chapter House's fortress.

— Brothers of the Snake.

Raven Guard

Agapito was dressed in black trousers and a sleeveless tunic. His arms bulged with muscles studded with the silvery wink of nerve shunt ports. His pale skin was shadowed by subcutaneous black carapace.

— Lord of Shadows.

Unnumbered Sons

His wargear was held in a makeshift armoury Daelus had set up at one side of the room. He left his armour on its stand and dressed himself in a loose tunic and trousers, pulled on his boots, and belted his bolt pistol around his waist. It was freezing in the station, but he didn’t feel it, and besides, nowhere was as cold as those millennia on board Cawl’s vessel. It was good to be out of his armour for a while. He had a loathing of confinement.

— The Great Work.

Areios had a few inches on the Firstborn Messinius. Neither of them wore their armour. Messinius was dressed in simple robes, Areios the off-duty uniform of short-sleeved tunic and trousers common to all the Unnumbered Sons.

— Throne of Light.

Knights Errant (early Grey Knights)

Clad in a long chiton of unadorned grey over a tan bodyglove with plastek-seals over his armour interface sockets, he was armed only with a few gardening tools hanging from a leather work belt.

— Luna Mendex.

Night Lords

In the Night Lords omnibus by ADB, the Night Lords are described as wearing robes or traditional Legion tunics (those of them that can still remove their armour, that is).

I hope this gave you a fair idea of how Space Marines might dress when they're not wearing armour. 😊

Well you're wrong

(except if you guessed Guilliman or sanguinius)

Primarch Garden Champions - The Ultramarines

The Champions are creations based off a template of various imperial heroes to assist their chapter in some way. Either by bringing their chapter back into compliance, reinvigorating it, or acting as massively powerful mascots. Unlike a regular Astrates, they will not need any organ implants or modifications in the future. They aren't as powerful as the Primarch Seedlings, though. And are a few years younger.

Of course the Ultramarines have the most Champions. Most of the other legions have 0-2.

There are none awkwarder than Corvo at a party:

-Not the Preserver of Histories, he who is called Infinite, Archaeovist of the Solemnance Galleries, Trazyn