The troops manning the suits are quite different to their firebat counterparts. As of 2504, 47% have never been to jail, and only 23% have ever been accused of murder. Marauder fatalities were commonplace prior to the implementation of kinetic foam into their suits, which allowed them to survive impacts that had previously killed operators, even while leaving the suit unharmed.
A variant, more powerful version of the CMC-660s used by marauders was approved for field testing, any any marauder who volunteered were compensated with credits.
The marauder can only attack ground targets. Its attack is more powerful against armored units; it may slow units, except for massive units.
The marauder is an early-game support unit, useful for supporting marines by slowing fast melee units. It is effective against armored units, like the roach. They are also powerful against stalkers, and, to a lesser extent, siege tanks, immortals and thors. Marauders can destroy buildings very quickly. The marauder is vulnerable to zealots, marines, and zerglings. As a general rule, a player battling zerg should build fewer marauders than usual, while against the protoss, marauders are effective, though work well with medivac dropships as a "commando force" when battling the former.
In Legacy of the Void, the marauder's attack was modified; it now deals 2 hits per attack instead of 1, but has the same DPS - this makes armor more effective against them. This was primarily meant to nerf marauders versus Protoss, but also makes the marauder much less effective against fully-upgraded ultralisks than in Heart of the Swarm.
In the Wings of Liberty campaign, marauders cannot use stimpacks.
A variant of the marauder appears in the mission "The Great Train Robbery," designated as a Dominion kill team. They deal slightly more damage than normal marauders and have a unique color scheme, but are otherwise identical to the normal marauder.
The marauder's attack slows non-massive ground units in target area.
Concussive Shells actually form a gravitational warp when they detonate. This warp not only damages the target, but it also slows the movement speed of all nearby units to a crawl for a short period of time.
Concussive Shells make marauders a great support unit against melee units, in addition to their traditional role of destroying armored targets.
Marauder armor can survive crushing impacts, but the same cannot always be said for the soldier inside. To help solve the problem, Wolfe Industries offers a Kinetic Foam undersuit that protects the soldier from the violent impacts the armor takes.
Surely the lives of your marauders are worth the small investment required to outfit them with kinetic foam.
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.
The following section contains information from a previous version of StarCraft II which is no longer valid.
The idea behind the marauder was to act as a sort of middleground between marines and vikings—mechanized infantry, yet not an actual mech.
The marauder was originally equipped with dual concussion-grenade launchers which reduce a biological unit's speed immediately by a set percentage. A charging zealot would still move quickly after being struck by a grenade.
Prior to StarCraft II beta patch #8, Concussion Grenades was an automatic upgrade. It later became a researched ability.
The Kinetic Foam upgrade in the single player campaign was originally known as "Ablative Scales". The original design for the button was even completed but was never used in the final product.
↑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.