The planetary cousin to the Standard Sci-Fi Fleet. While the Space Navy dominates the sky, it's up to the grunts to take the ground.
It is sometimes claimed that the use of militarized spaceships will make planetary forces obsolete. After all, why waste men and vehicles on the ground if you can just blast them from orbit with lasers, missiles, plasma bombs, or huge rocks?
The answer is simple: Unless you're going for genocide, you will need to be able to hold your new territory after you've blasted the defenders to ashes. If nothing else the invader needs a base to build supplies for his next glorious conquest. And of course he will want some subjects from which to collect the oppressive taxes needed to pay for his mighty fleet. Not to mention mopping up enemies not concentrated enough to warrant turning starship-grade weaponry on, pacifying local populations, and probably defending ground infrastructure or even taking targets that are too close to places you don't want blown up, or that are somehow protected against orbital attacks. (This is also the reason modern countries still have armies in the face of modern air power)
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Army Arrangement and Balance
Standard SF forces tend to follow the same lines as real world armies. If aliens are using said forces, there are going to be analogs to human ones.
Force composition varies, depending on the technology level and setting. Future armies tend to be armed with high tech gear and energy weapons. Post-apocalyptic works have a mix of decaying modern technology and improvised weaponry. Steampunk will go for steam-powered tech with a Victorian aesthetic. Of course, the writer's skill, knowledge and interest will also influence an army's depiction.
The most common models are:
Televised or animated programs: Rarely goes beyond basic infantry, tanks/APCs, and usually some kind of aircraft (unless there's the possibility of merchandising).
Tabletop and video games: Will have all of the below and then some, if they can fit.
Each army branch (Infantry, ships, armour, etc.) helps each other, balancing out any weakness. For example, Tanks have great protection and well-armed, but have poor visibility. Infantry are far less protected than tanks, but are smaller and can take advantage of the tank's blindness. Thus, the tanks need soldiers to protect against infantry, and the foot soldiers need the tank to deal with any enemy panzers.
For the major SF Army types, check out the Analysis section.
The Standard SF Army came be divided into several groups: Infantry (Standard and Irregular), Armored Combat Vehicles, Oceanic Ships, Aircraft, and Support.
Soldiers trained to fight on foot (or whatever limb used for locomotion), and has been used since the beginning of warfare. The most common unit used, often for storytelling purposes or they're cheaper due to logistical limitations (both in reality and in-universe.)
General Infantry (Grunts)
The basic infantryman who does most of the fighting. Variations include:
Light Used in skirmishes, scouting, pursuit, raids etc. Lacking heavy weapons, they're far more mobile than other infantry.
Line The standard grunt, armed with a primary weapon and a secondary weapon. If a series has nothing else, it will have these.
Heavy Armed with heavier equipment like Squad Automatic Weapons, Missile Launchers, or other BFGs. Like modern soldiers, these are typically found as part of a squad, rather than grouped separately.
Mechanized Travel via APC/IFV but disembark when needed. Occasionally supported by their armed transport, which provides heavy firepower. However, they require more resources for their vehicles.
Drop Troops Airborne infantrywrit large. They deploy into the combat zone directly from the ship or from a moving transport in the upper atmosphere, fully expecting to engage the enemy as soon as their boots touch the ground. Usually tasked to clear and secure landing zones ahead of the main force; as such, their role often overlaps with that of the Marines (which may be a source of Interservice Rivalry). Often overlaps with Super Soldiers - even if they pull from the same pool of recruits as regular infantry, they're expected to be a cut above the rest (largely because they have to be to survive the drop).
Power Armored Troopers wearing Power Suits - having improved protection, firepower, and capabilities. The proliferation of Power Armor will determine the role it plays in battle. Some settings have it common as dirt, and utilized by even the Grunts. Others reserve it for their Elite units, to give them an additional edge. In the middle, they may form an independent corps that takes the role of scouts, air support (if equipped with Jet Packs), light armor/fire support, and other specialized roles.
Marine Traditionally marines fall under the command of the navy, but often find themselves in the same fights as the army. Here, as in the past, the role of marines will be to gain initial ground in invasions and create a sizable perimeter to allow the larger and more mobile army to maneuver. They will also serve as guards aboard fleet ships and installations that escort the army to their combat zone, along with serving as EVA troopers and performing boarding actions against enemy ships. In a show which focuses almost exclusively on the fleet, any infantry will likely fall under this category. People who object to the word "marine" as smacking too much of Space Is an Ocean might choose to call them something different, like espatier, while still giving them the same basic job.
Provide specialized aid to regular grunts. Some are deployed in the rear lines providing maintenance, and others serve on the front lines.
Headquarters The Commander, his personal staff, and their support. The Commander, of course, commands the army. His staff provides him with everything he needs to command effectively, from situation and intelligence reports to his morning coffee. The supporting troops usually include logistical staff and pilots specifically tasked to get the commander what he needs and where he needs to be, as well as a security detail (which, if the commander is royalty or otherwise Very Important, may include the Praetorian Guard). Usually kept well behind the front lines and not featured beyond establishing who's in charge, but if given any real screen time, there's likely going to be at least one scene where the enemy makes a direct attack on the command post, giving the commander an Authority Equals Asskicking moment to show that he's more than just Armchair Military.
Logistical Clerks, supply officers, chaplains, lawyers etc. who fulfill the physical, mental, and spiritual needs of the soldiers.
Camp Followers Often a force on the move collects an assembly of civilian hangers-on to see to the various needs of the troops. While civilians are not technically part of the unit in question, they typically follow them from base to base (hence the name). Between civilian and military support, expect a force to carry around nearly as many staff as soldiers. Or possibly far, far more (the modern US Army has 10 support staff for every soldier actually in combat)
Engineers Technicians, Sappers, Seabees, anyone who is trained in repair and maintenance of technology and equipment. Sappers (combat engineers) and Seabees in particular actually see combat, as they either demolish enemy emplacements or build front line bases. Due to their intense combat experience and access to specialized equipment, combat engineers often fall under the elite category.
Intelligence Collects and studies information on the enemy. In the field, they may be interrogators who question prisoners.
Medical Doctors and Medics that save other grunts' lives. Perhaps due to the Hippocratic Oath, some medics are totally unarmed, or at least have difficulty firing their weapons. This will of course not be an issue if the enemy makes it a policy to Shoot the Medic First.
Pilots Whether its aircraft or tanks, vehicle operators are needed to move people around. Although valuable, there is a trend in SF in which aircraft pilots do Special Forces or even grunt work. Presumably so the writer(s) can have both ground and air/space action without having to double the cast. (The reverse — spec-ops soldiers that can also fly — is somewhat more believable but strangely rare.)
Used for providing security or police work. Typically not as equipped as Grunts, and usually not as effective. However, they are cheaper, plentiful, and useful in peacekeeping. Commonly sent with away teams or serving aboard ships, and a favorite of megacorporations. They can range from simple guards to gendarmerie units.
Any machine that supports or even takes the role of an infantryman, and at most the size of a grunt. Sometimes humanoid in shape, but not always. Robots are used by today's militaries, often for scouting, bomb disposal, and fire support.
Why stick to standard troopers, when you can create your own from scratch? Basically, any creature created through genetic engineering that is radically different from anything seen before. It can range from human variants to alien horrors. Sometimes, Artificial Biologicals can be even sized up, creating organic tanks, aircraft, or even ships. The drawback is that this requires high tech or powerful magic to do. Not to mention the creations could turn on their masters.
Racial Specialists In a group made up of several different races, the physical makeup of some species', for good or ill may set them apart from the other members of their coalition. They may be assigned special equipment that plays to their strengths or compensates for their failings.
Small teams who are created to deal with specific missions (rescue, counterterrorism, assassination, sniping, guerrilla warfare, training indigs, etc.) that regular Grunts are unable to. Special Ops tend to be at the peak of physical and mental perfection, making them supersoldiers in their own right.
Although not as common today or in SF, cavalry units do show up. Like their ancient counterparts, Cavalry are soldiers riding an animal. Unlike their ancient counterparts, they're limited to scouting. One advantage is that certain animals can go where vehicles can't and can cover more ground. In places where high technology is rare, it makes more sense to use horses or mules - they don't require any high tech equipment to keep running. If Cavalry is used in frontline combat, this means the army has technologically regressed or they're riding something so dangerous it could tear a tank to pieces. Other variants include:
Air Cavalry Close-knit helicopter and infantry unit performing recon and short raids. Developed during the The Vietnam War.
Armoured Cavalry Units that use ACV’s instead of warhorses, replacing them in their roles as shock troops or locating/holding down the enemy. King's Royal Hussars of the British Army is one example.
Non-standard military forces such as militias, guerrillas, or paramilitary organizations. Typically these forces are not part of the main military, but can be used in combat operations.
Covert units deployed by a nominally civilian group, such as an Spy Agency or a Megacorp. Like Spec Ops, they conduct secret and specialized missions. However, Black Ops are so clandestine that it's done outside of official and military channels. Such missions tend to be questionable, even outright illegal. Black unmarked uniforms and vehicles are typical. Can be assigned to regular military as support.
Sometimes the Army will be backed by local ("indigenous") forces, often in a temporary arrangement to accomplish the same goals. They can be militia, guerrillas, resistance fighters, or friendly aliens. Despite lacking regular equipment or training, they make up for it by having a better understanding of the locale. They're also more motivated to fight, having much more personally at stake. Sometimes, particularly when defending, this group includes local quasi-military forces like police.
Any infantry whose purpose is to accomplish their goals by targeting non-combatants and engaging in illegal activities that violates Interstellar law (i.e. rape, pillaging, murder, etc). Not utilized by honorable or good guy militaries, such units are used by less scrupulous forces.
Any non-military that are sent out for various reasons. Often, these tend to be either:
Scientists Whose knowledge is useful, especially when exploring or dealing with the unknown. Often in the rear, probably in some super-secret military base doing research. Other times they're out in the field.
The civilian is the main character, a recurring character, or having A Day in the Limelight. Expect their non-military perspective and/or specialized knowledge to save the day, over the objections of the troops.
Armored Combat Vehicles (Armor)
The other major component to a fighting force. Faster, stronger and carrying heavier weaponry most infantry can't. However, Armor requires maintenance: they need techs, spare parts, and fuel to keep on going.
Think Jeeps or Humvees, a lightly armed vehicle that can be used in a number of versatile roles for support (recon, transport of troops, etc.). In Real-Time Strategy (RTS) games, they're limited to scouting or anti-infantry roles. They may be given anti-armor weapons in order to make fast flanking or harassment attacks in support of Armor.
Heavily armored and armed all terrain units that are designed for frontline combat. The current kings of the battlefield, but not invincible. One of the biggest disadvantages is that tanks have poor visibility. The other is that tanks tend to require a lot of maintenance. In some settings, Tanks may become obsoletedue to technological developments. Infantry may be armed with Power Suits and Armor-killing rockets. Dropships become faster and can hit first. Mecha are so super, they outclass tanks.
In SF, tanks tend to hover, but not always. Tanks often come in several varieties:
Tankettes Rare, but occasionally seen (especially if toys are involved). About the size of a small car, and typically used for infantry support or recon. Think Tachikomas: fast and well armed, but against heavier tanks or even Power Suits they were outclassed.
Light Tanks Used for recon. They’re fast, cheap to produce and maintain, and usually can still pack a bit of a punch. In games, they tend to be underpowered, and as a result need numbers to take on heavier tanks.
Main Battle Tanks (aka Medium Tanks) Have a successful balance of firepower, mobility and protection.
Heavy Tanks Heavier and larger due to their greater armor and firepower. The greatest disadvantage is trying to produce them in great numbers. In Science Fiction, a surprising amount of these will have double-barreled turrets, despite the redundancy and problems of using them in real life.
Any legged ACV, often bipedal. Although not making sense from a military standpoint, mecha are very cool. Most are Real Robots, but using a Super Robot is not unheard of. It should be noted that in Eastern (especially Japanese) Sci-Fi, mecha are more likely to be of the "Giant Armored Soldier" type, while Western Sci-Fi seems to prefer the Walking Tank.
Spider Tanks Hybrid of a mecha and a standard tank, spider tanks provide the best of both worlds: the coolness of a mech and the practicability of a tank.
Mini-Mecha Either a one or two person cockpit on a pair of legs that typically has light weapons and armor and is used as a scout (which actually makes some sense); or a larger version of Powered Armor.
Any civilian vehicle modified for military use. Often used by Indigs/resistance forces, technicals are typically weak against military units. However, it does provide mobility when there is nothing else available.
If any wet navies are present, in all likelihood most (if not all) are submersible craft. Whether it's a carrier, battleship, torpedo boat, or destroyer, it can become submerged and still fulfill its duties below the surface. Common in which the ocean is the main setting or a post-apocalyptic world. For a full list of different types of naval craft see Types of Naval Ships.
Science fiction is apt to have Space Navies fulfill most roles the Air Force or Wet Navy would in modern combat. Space ships are in a good position to rain death from above and provide intelligence. However, a space force isn't always available, and thus aircraft must fulfill those roles when needed.
Common in video games, especially RTS, where the setting/genre limits space craft. Most (if not all) of these craft have VTOL capabilities. Outside of games, dedicated aircraft are often replaced by either Dropships, a Swiss army weapon (like a Mecha), or made obsolete due to some technological development that perfects Anti-Air defense.
Small unmanned unit that provides intelligence, maintenance, or firing support. Drones can cover more ground, are automated, and can save lives instead of risking people. The downside is the low durability, plus clear communications and technological requirements.
Small craft that deals with air superiority. Can be the same as a space fighter, but not necessary. It's main purpose is to attack other airborne craft.
Interceptors Lighter, fast craft designed to catch up with incoming targets. In Real Life, these craft sacrifice maneuverability for performance (such as speed and armament).
Provides battlefield intelligence, usually equipped with sensors and communications. Also used to provide early warning from incoming attacks. The more sensors, typically the larger and less maneuverable the craft becomes.
Designed to jam or confuse enemy communications and sensors, and protect allies from electronic attack.
Carry out specialized roles, such as transport, training, and fueling. These can be ground, air, or sea vehicles of varying sizes. In RTS games, these vehicles are unarmed for game balance.
Carryall Aerial transport that can rapidly deploy and pick up vehicles without the need to land. Like other Utility craft, they have no weapons.
Close Air Support
Designed to provide fire support for ground forces in coordinated strikes. Durable and armed with precision weapons. Typically, these craft lack any anti-aircraft weaponry and require fighter escort.
Deploys high explosives or strategic weapons on installations and other targets. Unlike Fighters, they have a greater range without refueling, and capable of attacking deep in enemy territory. Though they could be used for tactical strikes, Bombers are valued for their strategic importance. Because of their armament they have little in anti-air weapons. May require Fighter escort, but it could rely on stealth for defenses.
Fighter-Bomber/Strike Fighter/Multirole Fighters
Can both strike at ground targets and attack airborne targets. Cheaper to maintain, build, and equip than dedicated craft, and avoids being too specialized. There are trade offs, giving up advantage in some areas (such as the long range of a bomber) for generalized performance.
Sometimes, Dropships or transporters are not available, so these tend to show up. Versatile, they can be used for a number of purposes. Commonly used in transport and gunship roles.
Sometimes there are other air-support vehicles that aren't technically helicopters - turbofan vehicles are a popular choice for some reason - that show up in this role. Generally speaking though, they fly like helis, they fight like helis, and they'll probably get an Apocalypse NowShout-Out like helis.
The mid-point between a Bomber and the Airborne Warship below. The Flying Fortress is a large aircraft armed with a large array of guns, missiles, and/or bombs. Many are used as command vessels and may be capable of carrying troops on their own.
Large craft the size of naval ships, but capable of flight. Extremely well armed and armored, but tend to be slow. Popular in Steampunk settings, where they look like naval warships but with propellers or balloons. Futuristic works tend to go for a starship-like aesthetic, or simply have an actual spaceship fulfill this role. While Carriers are popular, Battlecruisers are also common.
Any units not meant for direct combat, but can aid in defense or back up other units.
Any unit or structure designed to take down aircraft, and sometimes even orbiting craft. In some instances, their weapons can be used on ground forces to great effect. Outside of RTS, it's rare to see a dedicated anti-air unit on the front line. Most SF tanks or infantry have some sort of anti-air weapon (or may have a variant armed with them). Such units are the reason why aircraft my be obsolete in a future war.
Any unit capable of firing large projectiles or energy weapons for indirect fire support. Could be rockets, shell-firing cannons, or beam weapons. In SF, these tend to be Self Propelled Guns, with light armor and treads/legs/hovercraft for movement. However, unlike a tank, Artillery is usually not designed for direct fire or taking hits. Often seen when Air or Space forces are too expensive to use or not around.
Any vehicle dedicated for officers to coordinate missions. Often filled with communications equipment and advanced computers to assist the General Staff. They often vary in size, from the size of a bus (serving as a mobile command tent) to little more than a jeep (carrying officers between command posts). Other times, they can be a modified tank or APC.
Another member of the Standard Sci-Fi Fleet, they can transport units from orbit to the ground and back again. It can also be used for transport or fire support, replacing helicopters in the gunship role.
Serves as a base for its forces, but is far more mobile and versatile. It may also provide fire support in battle. However, because of their size, they remain vulnerable to smaller units. Such a role may be served by a space ship.
Mobile Factory A common Real-Time Strategy fixture, where the base can also produce vehicles and weapons. A large ocean or spaceship is ideal - enough space to hold materials and machinery. Unusually, giant ground vehicles often fulfill this role
Any vehicle with sensors to gather battlefield data. Protected against most threats, including Nuclear, Biological, and Chemical weapons. In RTS games, such units are often used to detect stealth units.
Orbiting unmanned craft designed to facilitate communications or gather intelligence.
Kill Sat Can rain down destruction from orbit. It could be considered a superweapon, but not always. May be armed with an energy weapon, or it can drop a kinetic payload on top of a target.
Some people in the military may stand out more by their relationship to the main force than they do for the specific role they play in the fight. These include:
Free agents hired by the host nation to augment their own strength. Can be found in just about any role on the battlefield and at any skill level, from security forces to elite shock troops, although most portrayals lean towards the latter. If they're the good guys, they'll usually be highly professional (though they have an odd way of showing it) and follow a code of professional ethics that tells them to stick with a contract until it expires, unless their employer tries to screw them over. Villainous examples tend to be Only in It for the Money at best and Psychoes for Hire at worst, heedless of collateral damage and jumping at the chance to betray their employer for someone who pays better. Occasionally you'll get the odd band of Former Regime Personnel who are (generally) more ideologically committed, but even these guys are often more concerned about their own agenda than their host's well-being.
Mercenaries As above, but hired by the unit rather than on an individual basis.
Professionals brought in from a third party to provide training and guidance. They can be contracted by the state (like Hired Guns, and often drawing from the same sources) or provided by an allied power which can't or doesn't want to make their involvement more overt. Baron von Steuben and Lawrence of Arabia are famous examples from real life. May end up Going Native.
Soldiers from an allied military who fight alongside the main forces. In fiction, largely exist to create Jurisdiction Friction, since they often belong to another chain of command entirely and have different objectives, even when both forces are fighting for the same cause.
People who are drafted into the military, being forced to fight or provide services. These pressed men are reluctant to fight, and often questioning why the war is fought. Typically disinterested in military protocol and more interested in escaping the war.
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Anime and Manga
The Big O: Paradigm City Military Police, which consist of Security forces armed with IFVsand heavy artillery. Should they fail, at least a giant Mech shows up to save the day.
Blue Submarine No. 6: Considering most of the world is flooded, navies are the primary fighting force. The bad guys use biologically derived ships and infantry.
Dominion Tank Police: Focuses on a division of Police who drive around Tankettes. They're more dangerous to the city than the criminals.
Fullmetal Alchemist: Amestris' forces are dominated by infantry, with some primitive tanks, and the State Alchemists in the role of Exotic soldiers.
Full Metal Panic!: Mithril employs Special Forces that center around Mecha, which a submersible Carrier as a Command vehicle. Gauron and his forces are often Terrorists.
Ghost in the Shell and Ghost in the Shell: Stand Alone Complex: Focuses largely on a Cyborg Security/Special Operations group. In the anime, they have support from intelligent Tankettes. Regular military forces are armed with Spider Tanks and Power Armor (which make short work of the Cyborg Special Ops and Tankette group in open combat).
Gundam: Most of the attention is on the Mechs, but they're often supported by Armored Vehicles, Infantry, and other craft (Including Land Battleships, Mobile Armors, and Airborne Spaceships). Newtypes would be an example of Extoic Infantry/Pilots.
Neon Genesis Evangelion: NERV's primary offensive units are Exotic Mecha piloted by disturbed kids. The agency also employs a large amount of Support, Civilian, and Security personnel as well has its own aircraft and a wet-navy ship.
Robotech: In the Macross saga, the SDF-1 forces include an Aircraft and Troop Carrier (both submersible until the space fold, then they're just welded onto the ship, a number of atmospheric Aircraft, and non-transforming Mecha. The bad guys wear Power Armor, but are huge enough to take on mecha. The Masters saga featured Tank-transforming-Mecha, Anti-air batteries, and a Security branch for humanity. In New Generation, the Scott Bernard had to rely on a group of Indigs armed with Power Armor that could transform into Scouts.
To the Stars, a fic set in the far future of the Puella Magi Madoka Magica universe, has a fair few of these. The standard human infantry is a Super Soldier in Powered Armor, with extensive implants so they can be as effective as possible. They are accompanied by clouds of drones for deflecting incoming fire and improving firepower. The main character's grandfather is a medic, and the tech level is such that as long as the brain is intact, the soldier can probably be saved if they are recovered in time. Even with all of this, they're outclassed by the alien forces... except for the Magical Girl corps, who are all even more super than the Super Soldiers, and use magic to fill a huge range of roles, including air combat, space combat, black ops, stealth enhancement, and the like. The main character uses teleportation to turn her squad into hyper-mobile drop troops.
Aliens: The Colonial Marines are mostly Line Infantry, with Heavy infantry armed with smart guns. They also have transportation such as APC's and Drop Ships. The film also provides an example of Civilians: Burke plays the role of the Observer, Ripley as a consultant.
Avatar: The RDA has a personal army on Pandora, including tubrofan aircraft, Mecha, as well as regular infantry. The Indigs are the Na'vi, who rely on local animals to serve as Cavalry, both land and air.
The Matrix: In reality, the Machines have large armies of Robots, with special programs in the Matrix to serve as Security. Humanity relies on Special Forces that infiltrate the Matrix, since their only real weapons in the real world is poorly armored Mecha and hovercraft.
The 1980's movie Megaforce featured the titular mercenaries being armed with weapons "the most powerful science can devise". Using light vehicles like flying motorcycles and dune buggies, Megaforce's lasers and small missiles could destroy modern Main Battle Tanks.
Star Wars: The Empire relies heavily on giant, high tech Mecha, Elite soldiers and State Sec Troops. The Rebels rely heavily on Special Forces, with their necks being saved by the Indigs. The Jedi and Sith are Exotic infantry. The Prequels and Expanded Universe involves a large variety of combat vehicles.
In the prequels, the Separatist Confederacy and its precursor the Trade Federation relies on Robots as its main grunts. The Republic uses Super Soldiers (the regular clones) and Special Forces (the ARC troopers). The Jedi and Sith, again, are used as Exotic infantry and double as officers (the Jedi), civilian politicians (Palpatine and Dooku) and political officers (Maul, Ventress etc).
There's a few examples of atmospheric aircraft in Star Wars. The T-47 Snowspeeder seen in Empire Strikes Back is a civilian airspeeder converted to fulfill combat purposes by the Rebels. Another example is the V-wing, an atmospheric fighter-bomber used by the New Republic.
Star Trek V: The Final Frontier: With the transporters malfunctioning, Kirk attempts a rescue with a platoon of Starfleet troops. The Indigs still managed to overwhelm them.
Star Trek Into Darkness: When John Harrison attacks a high-level meeting of Starfleet's leadership, Admiral Pike calls for an air defense team. While Kirk is trying to shoot him down with a rifle, we get quick shots of a group of Starfleet soldiers with a turret trying to do so as well.
Transformers: Like the series, giant Mecha with Civilians. Unlike the series, the Mecha get support from Special Forces Indigs with close air support (plus Armor support in the sequel).
Terminator: Until Terminator Salvation, we only get to see brief glimpses of the war. Skynet relies on robotic aircraft, infantry, and even treaded Mecha. The Humans rely on infantry, in at least one time in the first movie, the use of Technicals.
The film version of the Mobile Infantry in Starship Troopers seems to consist solely of basic troopers and drop ships (compare to the other versions listed below). The Bugs have castes that act as tanks and aircraft and others though.
The Bolo series by Keith Laumer, later by David Weber, largely focuses on the AI-controlled Supertanks.
CoDominium: During the CD era on the colony worlds, Infantry was king, aircraft gone due to technological developments, artillery valuable, and a single tank could decide a war.
The Childe Cycle of Gordon Dickson: Largely focuses on infantry, but Armor does exist.
Dune: Because of the existence of effective force field tech, infantry is king. This changes on Arrakis, where the use of shields attracts the dangerous native lifeforms. The Baron Harkonnen uses this to his advantage by using Artillery, considered obsolete thanks to the shields. Super Soldiers like the Sardaukar and the Fedaykin of the Fremen dominate warfare. The Fremen are also Cavalry, using the giant Sand Worms as their steeds. APCs, Drop Ships and various military aircraft also exist, at least judging by the first novel. No mention of tanks or mechas. Firearms vary wildly, lasguns are often Cool, but Inefficient due to the aforementioned force fields (a laser hitting a field would cause a nuclear explosion). Melee weapons see much more prominent use than in most sci-fi settings. Mentats, Face Dancers and the Bene Gesserit can be considered Exotics.
Hammers Slammers: The titular mercenaries largely employ tanks, supported by Artillery and infantry. Instead of using APCs for transport, the Slammers use open-topped armored cars. Although the Indigs and assorted mercenaries they face are not as well equipped, they still can pose enough a threat to Hammer's men.
Honor Harrington: Although most of the focus is on space combat, ground combat also appears. The major sides typically employs marines in Powered Armor, and separate armies. During the Committee of Public Safety, Haven's armed forces included an increase of political units. Tanks exist in the setting, but are considered largely obsolete due to the mobility that the Power Armored troops have combined with some of the more powerful weapons they carry, and thus are seen very rarely. Occasionally, we see the Space Marines of various powers (Manticore, Haven, and the Solarian League Navy) used against unarmored enemy infantry, terrorists, or indigs. The resulting battles are brief.
Legacy of the Aldenata: Dominated by Infantry (especially Powered Armor) and Artillery, since the Posleen anti-air shoots down any aircraft very effectively and many Posleen weapons trivialize Earth-built armor. Oceanic navies also play a role. The one instance of a Civilian going along with some Generals to prepare Earth for the Posleen ends horribly.
Starship Troopers: An example in which Powered Armor is in common use, and their support comes largely from orbiting craft. For the Bugs, the Warrior Caste serve as their Infantry. A supposed psychic (officially called a "gifted", and the narrator suspects he just has very good hearing) is an example of a Exotic soldier.
The War of the Worlds: The Martians use Mecha, and their technology is so advanced that the Indigs (19th Century British army) are barely a match for them. Artillery and Warships take down a few Tripods.
In addition to Mecha, the Martians are said to have used 'Flying Machines'. Exactly what Aircraft category they would fit under is unclear, since the protagonist does not see them during the course of the novel (they're a rumour, albeit one that is said to have been confirmed after the War) and the Indigs lack any real airpower, but they are indicated to have bombing capabilities.
Bill the Galactic Hero has served in a number of different military roles, including Security, Special Ops, and (of course) a plain old grunt.
The Confederation of Valor series mostly deals with line infantry who wear low-key Powered Armor, understandable since the main character is a sergeant in such a unit. They're generally transported to the battlefront by air. The series also has aerial fighters, tanks, and artillery, as seen during the full-scale battle in book four.
The Hunger Games: Panem Peacekeepers serve as State Sec Troops, guarding the Tributes and enforcing order in the districts, and utilize hovercraft for aerial roles (from combat to transport to patrols).
Andrey Livadny's The History of the Galaxy series are mostly focused on ground combat (despite being a typical Space Opera), so this trope is present. Since the setting spans over 1000 years, the realities of ground combat change. At first, standard mechanized infantry and tanks are the norm for the Earth Alliance. Then their attempt to their the Dabog colony with this type of army utterly fails when the colonists use their serv-machines developed from studying the local dinosaur-like predators. After the Earth Alliance develops their own walkers, and the Free Colonies start to copy those developed by Dabogans, infantry becomes pretty much useless, and all ground combat is done by mechs. Since the Earth Alliance is much more advanced in the fields of AI and mind-machine interface, resulting in very effective serv-machines of the dreaded Hoplite and Phalanxer designs, the colonists decide to try a new approach and start mass-producing fairly primitive and cheap (smaller) computer-controlled drones called LDL-55 (walkers armed with a 200-megawatt laser) and MX-300 (treaded RPG launchers), whose primitive AIs are at their best when networking together. Later on, the Earth Alliance also develops combat androids. After the war, the victorious colonists form the Confederacy of Suns, and retire most wartime weapons, including the mass-produced drones. They do keep some serv-machines but choose to adopt the more effective Earth Alliance designs rather than their own Golden Eagles. Mechanized infantry is once again used for small-scale conflicts, and some later start wearing Powered Armor. There are no dedicated atmospheric fighters. All fighters are of the aerospace variety and are, thus, part of the Standard Sci-Fi Fleet. However, most serv-machines are equipped with short-range boosters allowing for limited flight.
The author has made a clear distinction between the various types of serv-machines. Only four are ever named: Hoplite, Phalanxer, Raven, and Golden Eagle. The latter is a Free Colonies design retired after the First Galactic War. The Hoplite is a relatively light model (about 20 metric tons) and is primarily used for scouting and close-range combat. The Phalanxer is a Mighty Glacier (about 60 metric tons) and is mainly designed for long-range bombardment of targets pinpointed by a Hoplite (they often form combat pairs). After firing, the Phalanxer can drop its back-mounted heavy missile launchers and act in a more combat-heavy role. The Raven is only really used in a few novels. Sometimes, it's portrayed as a third, medium type (40 metric tons) complementing the Hoplite and the Phalanxer, while other times it's portrayed as a unique model incorporating the best of both designs. All three models have advanced AI and mind-machine interfaces, allowing the pilot to "meld" with the AI and control the mech without using any controls, with the AI eventually learning from the pilot and improving. Standard serv-machine weapons include Magnetic Weapons, Frickin' Laser Beams, and missile launchers. Point Defenseless is averted, as they're also equipped with laser defense grids. Advanced AI also allows for Magnetic Weapons to fire Pinball Projectiles, especially if another serv-machine has pinpointed the target.
Babylon 5: The Earthforces we see in most episodes are from Security branches. Regular Army are informally known as GroPos (a contraction of "Ground Pounders") and seem to have the standard mix of personal arms & body armor with squad support weapons. Close Support Aircraft are seen in battles that are stated to be pure Army.
SeaQuest DSV: Considering the oceanic setting, it's no surprise that advanced submarines are the main focus. The good guys also deploy Kill Sats, and psychics and dolphins for experimental use. The main ship got stuck with civilian Teen Genius. The UEO experimented with Super Soldiers, which didn't go so well.
Space: Above and Beyond: Both Humans and Chigs seem to rely heavily on infantry for ground combat. Pilots are also used for grunt work, although justified within the show. Armored vehicles are used occasionally by both sides.
Stargate SG-1: Because the Stargate is only 20ft across, infantry dominates interstellar warfare. The U.S. Air Forces does use robots for drones, scouts, and logistics. Cruise Missiles and Drone Attack aircraft are often launched through the Gate to soften up hardened targets. Scientists are sent along to provide advice and support during exploration. The actions by the rogue NID and the Trust are examples of Terror units.
O'Neill: What kind of archaeologist carries a gun? Jackson: *Raises hand* Uh, I do. O'Neill:Bad example.
Starfleet typically sends down Security force with away teams or on certain missions. It's not until Deep Space Nine that we see any ground warfare. Everyone appears to rely largely on Infantry. To make sure their own Supersoldiers stay loyal, the Dominion addicts all their troops to a chemical agent and sends a civilian to act as a drug pusher. An episode of the original series had Starfleet personnel using a photon mortar, but the weapon never appeared again afterwards. The heroes were once on the receiving end of a Klingon mortar in DS9, but the rounds were so laughably weak (and seemingly completely lacked shrapnel) that they had to land directly on someone to do more than annoy them.
Star Trek: Enterprise finally shows dedicated Space Marine-like troops. The MACOs operate in small squads and are usually seen on ship boarding actions, although a few episodes show them deployed on planets. They receive special training and carry rifles with custom mods, while any fleet officer usually carries a phase-pistol.
BattleTech: Mecha dominate the battlefield, but infantry, tanks, and aircraft are still around. The Clans manage to develop Powered Armor (Elementals) and Mini Mechas (Protomechs) that can take on full-sized mecha.
Warhammer 40,000: Another example in which almost every single unit type is included. It is also notable for popularizing:
Political units, notably the infamous Commissars.
Elites/Supersoldiers: The Space Marines, and several Imperial Guard Units
In Rifts, where small arms are capable of slagging a 20th-century Main Battle Tank or vaporize a human, tough armor is a necessity. Also, Armored vehicles (from bikes to tanks), aircraft, Powered Armor and Humongous Mecha of many different types and configurations are available to mercenaries and independent adventurers, to say nothing of official military forces. Exotic troopers can include cyborgs, chemically-augmented super-soldiers, psychics, and depending on the individual force, even magic-users, mutants, and Dragons.
In Traveller the state-of-the-art armies use Powered Armor for a good chunk of their infantry and grav vehicles for cavalry/armor. Rapid-interface units (Space Marines, though only some of these are actually called marines) and the like, have suits that allow them to jump directly from orbit like paratroopers. Artillery is provided by missile launchers and in the case of the Third Imperium, meson guns. The army of the earlier Terran Confederation also contained a number of security divisions specially trained in hearts-and-minds work among conquered Vilani. The Zhodani had specialist commando units with psionic abilities and used Robot troops.
Star Grunt II is a miniatures game that focuses on the infantry, especially the grunts. However, Powered Armor, AP Cs, air transport and gunships, and artillery are common elements. Tanks are less common, but are supported by the rules. This inlcudes a sample scenario which provides an object lesson in what happens to tanks without infantry support.
Tomorrow's War has rules for everything except Humongous Mecha and Land Ships. As well as for "Irregular" troops such as insurgents.
Advanced Wars: For the most part, the military units in the games are nothing fancy until AWII. Then the game introduces quasi-Spider Tanks, giant lasers, and the Black Hole forces look high tech. By Dual Strike, they've added Supertanks to their arsenals.
Battalion Wars features Grunts and Heavy Weapons specialists of various types for infantry, and recon, Light and Heavy Tanks, specialized vehicles such as Anti-Air and Artillery, and Multipurpose Fighters and Bombers. It also includes a Supertank in the Battlestation and a Flying Fortress for many factions. The sequel adds naval craft as well.
Sid Meier’s Alpha Centauri: The games has a number of chassis types, including Infantry, Aircraft (mid-game "Needlejet"—i.e. fixed-wing aircraft—and "Copters", and late-game "Gravships"—basically fan-propelled zeppelins lifted by Anti Gravity instead of gas), Oceanic Craft (early-game "Foil"—i.e. hydrofoil—and mid-game "Cruiser"—i.e. keeled ship), Speeders, Hovertanks, etc. In addition, the local Mindworms play the role of Exotic Indigs.
The Expansion Pack introduces two alien factions, who have the same types of chassis as humans. They actually start the game with an Ogre-class Spider Tank/Humongous Mecha, however, they lack the tools to repair or make more of them.
Command & Conquer: Almost every single infantry and vehicle could be found in these games. Although Tiberian Dawn and Red Alert armies are largely conventional, even they have vehicles that are fantastic (Turbofan Orcas, Chronotanks, Mammoth Tanks, and Stealth Tanks just to name a few). As both the Tiberium and Red Alert series' progressed, they got more and more sci-fi-ish, with Tiberium going futuristic and Red Alert going more Pulp-fantastic.
This, while Generals on the other hand mostly remained realistic, with only very few true Sci-Fi units. Examples are mobile Cruise Missile Platforms, anti-missile lasers and laser cannons, missile jammers, HollywoodHackers, and the occasional GLA stealth unit, who are World War II tech-using vaguely-Islamistish terrorists.
Dune II: Unlike the books, the Dune RTS games have a wide range of infantry and vehicles. Emperor: The Battle For Dune had the Tleilaxu provide Biological monstrosities as units. Many armored units are now Mecha. The Sardaukar and Fremen subfactions count as Supersoldiers, while the Guild ground forces are considered Exotic.
Halo: Dominated largely by infantry (from Light to Elite, and of course the Super Soldiers), although both sides use field aircraft and at least one Armored vehicle. Halo Wars expands on this, giving the UNSC Heavy and Elite infantry (the Hellbringers and Helljumpers respectively), APC's, and Anti-aircraft units. Several of the Covenant vehicles are effectively Technicals, being repurposed mining equipment.
Metal Gear Solid: Since Metal Gear, the series has involved the titular Mecha or mentions the machines. MGS introduces genetically engineered Special Ops, as well as truly Exotic troops. As the series progresses (save MGS3), the more Sci-fi elements begin to emerge. And even then, Metal Gear Solid 3 involves psychics, a hundred year old sniper with photosynthetic moss in his skin, a jet pack-wearing insane cosmonaut, a guy with superman speed, someone who could control hornets, and a supertank.
Military Madness (aka Nectaris) follows the basic setup for their armies. Since its set on the Moon, the infantry are naturally wearing power armor. In the Playstation 3 remake, the Buggies are renamed Technicals.
Starcraft: Powered Armor, Mecha, and Supersoldiers are common. Terrans have Moblie Bases and their "Ghost" units are Exotic Special Ops. The Protoss are Exotic by nature, and most of their vehicles are Technicals (being reprogrammed maintenance machinery) . Although most Zerg are technically infantry, they have different breeds that fulfill the various roles in a Sci-Fi Army.
Tanarus: Tanks are the primary focus of the game, mostly of the Main Battle Tank and Hover Tank variety.
Total Annihilation: Infantry roles are replaced by Mecha. The game is also notable for the its Commander unit. Should the Commander be destroyed, often it's game over. This is carried over to its Spiritual SuccessorSupreme Commander, which includes tanks, mechs, aircraft, and naval units. It also has the Commander unit, along with powerful Experimental Units.
X-COM:The Humans fight with advanced Aircraft and Special forces w/Tankettes. The aliens deploy a wide range of Infantry, including Exotic psychic forces, and literal Terror units. Some player guides encourage players to develop their ground forces along these lines as well, with specialists and roles.
In UFO: Enemy Unknown (or XCOM: UFO Defence, if you like) and XCOM: Terror From The Deep the best (and only sensible) tactic was to make everyone wear Flight Suits or Magnetic Ion Armor and train hard in psionics or MC control and wield BFGs. No need to specialise, just make everyone unstoppable psychic flying deathmongers.
The Firaxis remake diversifies X-COM soldiers into various classes, including Assault, Sniper, Support, and Heavy, and develop abilities along those trees as they level up. Those who are discovered to have the Gift become Exotic forces in addition to their combat class (they can also wear a special armor that boosts their abilities). In addition to Cyberdiscs, the aliens now employ small Attack Drones that repair nearby friendly (mechanical) units and fire a small particle cannon. With some research, X-COM soldiers can capture them to use them for the mission.
The Bureau: XCOM Declassified has Outsiders also using gunships in some missions. Initially, they're a big threat, as they make cover useless. Later, though, with the use of more powerful weapons and abilities, they become fairly easy to kill. The Outsiders themselves have many different classes within the same race, including common soldiers, commanders, tech-commanders (i.e. shield-enhancers), psionic commanders, snipers, scouts, etc. Your own agents can be chosen from one of four classes: Commando, Engineer, Recon, and Support. Your Player Character is a unique Squad Leader class with separate abilities.
Rebelstar: Tactical Command, a spiritual successor to X-Com: UFO Defense, focused mostly on Infantry. Each side had their own special units: The Humans had weak robots, the Arelians had flying saucers, the Zorn had either giant green alien dogs or dinosaurs, and the Frylar had flying bugs and flame tossing giant beetles.
The Expansion Pack adds the Phoenix Mercenaries, a breakaway group made up of former Crayven mercs who have decided to strike out on their own. Their tech is similar to Crayven, for the most part, with a few additions.
The sequel takes place 300 years later, although the units of the two human sides are suspiciously similar to the first game, with the Terran Empire using energy weapons and hoverdynes and the Northern Star Alliance using ballistic weapons and terradynes. This is justified in-story, as the Terran Empire was prospering for nearly two centuries, while the outer colonies were isolated and suffered regression before forming the NSA. Also, many of the NSA planets were colonized by the Crayven Corporation, justifying the tech. The game also adds walkers for the Empire, and helicopters ("helidynes") replace aerodynes as air support. The dropships are no longer the bulky kind and can be turned into the most powerful unit in the game with upgrades. The Virons are similar in terms of ground troops, except for their ability to merge and "un-merge" into new units. Their ground vehicles hover but are called "centruroids".
FEAR has a general mixture of various infantry types in the form of the Replica soldiers, who are vat-grown clone troopers who respond to the commands pf psychic commanders (simultaneously fusing Biological, Exotic, and Super Soldier in one package). Within the Replica are specialists; Elite Replica troops in heavy armor, enormous Heavies that are bigger and better armed and wearing oversized armor suits, Spec Ops units in the form of the Assassins, and mechanized support piloting REV Mini-Mecha suits or Elite Powered Armor suits that essentially serve as walking light tanks. Finally, there's robotic units in the form of light "Mech" units which are small bipedal walkers about as tall as a human.
Jeff Wayne's War Of The Worlds: Similar to the Literature example above, but humans are on an even war footing with the Martians. The Human arsenal has been expaned with tanks, armored cars, self-Propelled artillery/anti-air, and a balloon. The Martians forces now have Recon, Exotic telepathic, and various construction units.
MechWarrior Living Legends, unlike previous MechWarrior games note which only had mechs for the players, as other assets were just Cannon Fodder in the singleplayer mode, is a combined arms game (similar to the Battlefield series). The standard warfare unit is the BattleMechwalker, which varies between 20 to 100 tons. The mechs are the most adaptable asset, occupying almost any role, depending on the chassis and its loadout. Aerospace fighters occupy the Dogfighter, interceptor, bombing, recon, close air support, and the VTOL assets function like helicopters and are used primarily for harassment and scouting. Tanks vary from 20 to 95 tons, and come in several flavors; treaded, wheeled, and hover (as in hovercraft with skirts and fans). Tanks are more durable than mechs, but slower, and generally very specialized, such as only equipping Anti-Air weapons. APCs work as resupply points for ammo, and as a spawnpoint for infantry. The game lacks standard infantry, and instead has Powered Armor, which has a jump pack, missile launchers, a big load of grenades in several flavors, and can carry two weapons, such as lasers or autocannons.
The Voth in Star Trek Online's Dyson Battlezone have a mix of various types of infantry (everything from line infantry to special forces) and mecha. They also use genetically engineered dinosaurs as everything from supply runners to the equivalent of main battle tanks.
In Schlock Mercenary, mercenaries and what we've seen of military forces use various flavors of infantry and armor. They seem specialized for enclosed spaces and other situations where calling down death from orbit isn't an option, so there's not a lot of variety - no indirect fire's been shown. Everyone gets Power Armor. The setting's Deflector Shields are based on gravity control, so most things fly, and the line between armor and close air support is blurry. The closest thing to other aircraft roles is a spaceship with a crew that's been annoyed enough to come down there.
Exo Squad: Both sides rely on Exosuits (a cross between a Mecha and Power Suit). The human ExoSquads are supported by jet-pack powered light infantry. Human resistance forces play the role of Indigs (some of them have jetpacks too). The Neosapiens develop Supersoldiers, some focusing on brute strength, others on mental capabilities.
G.I. Joe: Special forces versus Terrorists, usually with lots of vehicles for just about every niche listed above that could sell as a cool toy (and often did, usually with a certain bit of overlap when you line them up all together).
Roughnecks: Starship Troopers Chronicles: the CGI series actually have Power Armor for the humans. Like the Zerg, the Bugs rely on Infantry variants to act as artillery and other units (including spaceships).
Sonic Sat AM: The Saturday morning cartoon had Robotnik run a force composed of Robotic Grunts, Mini-mecha, Attack Drones, and Bombers. The Freedom Fighters have to make due with simple Infantry.
Transformers: The series focuses on sapient alien Mecha, with the good guys often dragging along Civilians (which even worse in the Anime Unicron Trilogy). There is basically no division between infantry and mechanized vehicles, air support, or technical and support functions. The skill and power of individuals generally trump any organized battle plan.