Combi-weapons are a variety of Space Marine, Chaos Space Marine and Ork weaponry derived from the integration of multiple different weapon types into a single weapon. There are two major types of Combi-weapons. The first combines two identical weapons into one larger weapon, giving the resulting weapon system a higher rate of fire and better accuracy by virtue of simply throwing more shells, heat beams or plasma at the target. The second type of Combi-weapon is an amalgamation of two wholly different weapons into a single casing. Only one component of the combined weapon can be fired at a time, and often the secondary weapon has very limited ammunition, enough for only one shot or short burst of fire. Such weapons augment the bearer's tactical flexibility, granting him a limited capacity to deal with threats that the main weapon would find hard or impossible to damage.
- Bolter-Flamer - A standard Bolter with a Flamer attached to the side, useful for close combat.
- Bolter-Grenade Launcher - A standard Bolter with an underslung Grenade Launcher that is most useful for assaulting or defending against a large group of foes.
- Bolter-Meltagun - A standard Bolter with a Meltagun attached to its side, used as an anti-armour weapon.
- Bolter-Plasma Gun - A Standard Bolter with a Plasma Gun attached that is useful for a variety of tactical necessities.
- Combi-grav - This relatively rare Combi-weapon variant incorporates a single-shot Grav-Gun, allowing the wielder a potent graviton attack when the fighting is fiercest without sacrificing the formidable wrath of the standard Bolter. The Combi-grav incorporates a standard Astartes Pattern Bolter with a Grav-Gun as the secondary weapon.
- Twin-Linked Bolter - Similar to the Storm Bolter, the Twin-Linked Bolter or Combi-Bolter is simply two standard Bolters that have been mechanically combined into a one weapon, rather than having been constructed that way in the first place like a Storm Bolter. The Combi-Bolter was much more common during the Horus Heresy era than at present in the Imperium and Chaos Space Marine Attack Bikes are still often equipped with the Combi-Bolter, though the Storm Bolter has replaced it in standard Imperial usage.
- Bolter-Needle Pistol - A Bolter with a Needler integrated within it, intended to be used against creatures like daemons that are extremely difficult to injure. This Combi-weapon is used only by the Inquisitors and Acolytes of the Ordo Malleus. A variant of this Combi-weapon also serves as the primary weapon of Eversor Assassins.
- Bolter-Stake Crossbow - A standard Bolter that has been integrated with a crossbow that fires wooden stakes. This weapon has been used by the Inquisitors and Acolytes of the Ordo Hereticus against rogue psykers.
- Condemnor Bolter - A Condemnor Bolter, also called a Condemnor Boltgun, is an Imperial Combi-weapon that couples the iconic might of the Imperial Bolter with a secondary launcher in the form of a single-shot crossbow armature that fires blessed silver stakes engraved with sigils of disruption. These are particularly deadly to Chaos-corrupted psykers. A direct hit from the crossbow component of the Condemnor Bolter will therefore not only deal a severe physical wound to an enemy psyker, it will also send his or her power spiralling out of control, consuming the user in a storm of untramelled psychic energy. The Condemnor Bolter is the ultimate man-portable implement of judgement against those who wield the unclean energies of the Warp. It is a weapon favoured almost exclusively by the Witch Hunter Inquisitors of the Ordo Hereticus such as Katarinya Greyfax.
- Shoota-Skorcha - The Shoota/Skorcha is a Kombi-weapon that provides the user with close-range firepower from a Flamer on a secondary, undermounted barrel beneath the Shoota's primary barrel.
- Shoota-Rokkit Launcha - The Shoota/Rokkit Launcha gives the user a single side-mounted Rokkit Launcha with a single Rokkit to use against enemy tanks and armoured vehicles.
- Twin-Linked Shoota - The Twin-Linked Shoota is often used by Ork Warbosses. It provides greater accuracy than a standard Shoota.
- Black Crusade: Core Rulebook (RPG), pg. 157
- Codex: Grey Knights (5th Edition), pg. 55
- Codex: Space Marines (6th Edition), pg. 121
- Dark Heresy: The Radical's Handbook (RPG), pg. 153
- Deathwatch: Core Rulebook (RPG), pg. 146
- Deathwatch: Honour the Chapter (RPG), pg. 128
- Imperial Armour Volume Eleven - The Doom of Mymeara, pg. 118
- Imperial Armour Volume Twelve - The Fall of Orpheus, pg. 33
- Specialist Games Catalogue, pg. 107
- Warhammer 40,000: Wargear (4th Edition), pp. 42-43
- Warhammer 40,000: Wargear (2nd Edition), pg. 70
- Warhammer 40,000: Rulebook (6th Edition), pg. 54