Operating in squads, reapers specialize in hit-and-run, close-quarters combat. Classified as foundational units for terran forces, they are more mobile than marines as their jet packs allow them to surmount obstacles independently. Originally these jet packs (alternatively referred to as "jump packs") were capable of full flight. Crashes and fatalities were common among new "recruits" as the unwieldy booster proved difficult to control. The hardware was also known to randomly explode due to poor distribution of fuel lines and air intakes, leading to a complete overhaul. Prototypes of a flightless, twin-turbine jump pack surfaced soon after—which gave reapers enough mobility to carry out their missions and return to base in one piece.
Dominion reapers consisted of individuals that are resistant to neural resocialization—pirates, petty
crooks, murderers, the occasional political dissident, and marine recruits that remain unmanageable after being subjected to resoc. These resistant recruits tended to be among the most hardened of criminals, and were sent instead to the "Icehouse" in the Torus system to be inducted into the Reaper Corps. Reaper recruits were chemically altered to make them even more aggressive before being subjected to brutal training in close-quarters combat and the use of their jet packs.
Reapers were obligated to serve two years before being discharged. In the first five years the Reaper Corps failed to have a single recruit complete more than six months of service. However, some reapers were allowed to leave the program for reasons such as injury.
Upon coming to the throne, Valerian Mengsk re-organized the Reaper Corps, giving its members better, more humane training. He did away with the requirement to use dangerous stimulants, and focused recruiting on finding candidates who were naturally unpredictable.
Reapers can leap up and down ledges (only one tier, however) without the need of a spotter or medivac dropship. This ability makes reapers ideal for scouting and hit-and-run attacks. They cannot leap over obstacles or Force Fields, however.
The reaper's low damage attack ignores the specially hardened shield of the protossimmortal and cannot hit air units.
Dustin Browder believed the reaper was over-nerfed in the development of Wings of Liberty and intended to correct that in Heart of the Swarm. Blizzard believed the reaper was only strong in a short period of gameplay.
In early game raids, reapers work well in trios. A trio of shots can take out a drone in a single round of firing for instance.
The reaper is not quite as fast as the hellion, but can often get to certain areas faster due to its cliff-jumping capability. Reapers do more targeted damage to light-armored units such as workers but hellions can injure several simultaneously and with the Infernal Pre-Lighter upgrade are capable of dealing greater amounts of damage. However, reapers attack more than twice as fast as hellions do. They have different armor qualities as well, which can factor into the decision as to which raider to use.
Attack upgrades improve attack cooldown of affected units by 5% per level.
These self-replicating ultra capacitors reduce the reload time of weapons and systems. Now each of the weapon upgrades at the armory and engineering bay increases attack speed by 5% in addition to increasing damage.
Armor upgrades increase health of affected units by 5% per level.
We have created a new lightweight alloy called vanadium. Vanadium diffuses weapon impacts much more efficiently than traditional armor plating, and it better preserves the life of our units. Now each of the armor upgrades in the armory and engineering bay increases unit life by 5% in addition to increasing armor.
↑ Reapers are actually one of the best units against any light units in the game. They kill Zerglings, workers, and even Zealots pretty well with a little maneuvering. Their mines also decimate stationary defenses, as well as tech buildings. They are no doubt one of the best raiders in the game right now.
Marauders on the other hand are probably better mixed, unless you are going up against an all armored ground force. Marauders work well against both Protoss and Zerg. Early game, as mentioned above, they are great for slowing Zealots while Marines do the damage. Against Zerg, they are better suited against those pesky armored Roaches with the fast regen. Karune. 2008-10-21. Reapers and Marauders. Battle.net StarCraft II General Discussion Forum. Accessed 2008-10-21.
↑ The Hellion is faster than the Reaper side by side, but the cliff traversing talent often gets the Reaper to the place you want to go faster.
In raiding, it really depends. Hellions will be able to hit several workers at the same time, but Reapers have much more direct damage. Choosing what to use may also depend on what you are up against. Hellions are armored, whereas Reapers are light armor. Both are very useful for raiding and used in conjunction effectively could easily mean GG quite early, bleeding the enemy economy and tech. Karune. 2008-09-26. Karune, Is Hellion Faster than the Reaper?Battle.net StarCraft II General Discussion Forum. Accessed 2008-09-26.