A guide to Reivers and how they will function from the Warhammer Community. They have an amazing number of attacks and dual wounds. Interesting that they inflict Terror reducing the leadership down by one for nearby units. Definitely these guys are set up to disrupt the enemy lines.
via Warhammer Community
https://www.warhammer-community.com/2017/07/10/tactica-primaris-space-marine-reivers-july-10gw-homepage-post-2/
Reivers possess the same strength and durability as the rest of the Primaris Space Marines – like Intercessors, they have an additional Wound and an additional Attack compared to a standard Tactical Marine representing their enhanced physiology. In addition to this, these warriors have the same armour saves as other power-armoured units, so they’re going to require some concerted effort to displace and should be able to last a long time in combat against any unit that lacks armour piercing weaponry.
For weapons, the Reivers are equipped with heavy bolt pistols and combat blades. Effectively, this is a very similar configuration to most assault units and will function just as well, piling on a huge number of potential hits. Each Reiver will be attacking 3 times in the fight phase, meaning that even a small squad has a high potential damage output. Compared to an Assault Squad, you’re trading the ability to take special weapons for more Wounds and more Attacks. The heavy bolt pistols are very useful – unlike most pistol carrying units, these aren’t just an additional free shooting attack but also modify the enemy’s saves by -1; possibly enough to contribute key casualties to a difficult combat.
Where the Reivers really shine is with their special issue wargear and abilities. The shock grenade, in particular, makes the Reivers very dangerous, as it prevents enemies from firing overwatch and subtracts 1 from their hit rolls. Used to directly support the Reivers and other assault units, this is a great way to mitigate your opponent’s defences against charges, such as units that possess additional Ballistic Skill when firing overwatch or flamers. By modifying hit rolls, these also allow the Reivers to maximise their effectiveness as disruption units, using their grenades to weaken one shooting unit and then charging another to tie it up in combat.
The signature rule of the Reivers is called Terror Troops and represents their terrifying presence on the battlefield. In-game, this forces nearby enemy units to subtract 1 from their Leadership. Like shock grenades, you’ll have to be deep in enemy lines to maximise the effectiveness of this ability, but it’s worth noting that this doesn’t just directly aid the Reivers themselves but also their fellow Battle-brothers. If one of your opponent’s gunline units is caught fighting Reivers, units within 3” will also be suffering penalties to their Leadership (we imagine that if a bunch of skull-faced giants were tearing up your mates, you’d be a little demoralised as well). In practice, this penalty is a great way to rack up more losses from morale for your opponent, either in thinning out hordes or attempting to force losses against more elite units.
