Support Power

In the Real Time Strategy genre, sometimes the player is permitted to receive support in one form or another from things that are not included on the in-game map. This allows for a greater variety in the game play without introducing additional units into the game, as well as enhancing the sense that the player is part of a larger army, and that the tiny, Invisible Wall bounded battlefield is in fact not the edge of the universe, with all production, training and fielding of units occurring inside of it.

Support Powers in contemporary games will almost always have a user interface icon on the side of the screen, and are used by clicking on this and then selecting a spot on the battlefield to apply it to.

These come in several forms.

Type One: Experience Points are earned through RPG Elements. When a sufficient amount has been accrued, the player earns "points" which are then spent to "buy" from a range of available abilities. These are usually, but not always free once the ability has been gained, with a timer limiting how frequently it can be used. These are typically tied to the HQ Building, so if you lose that you won't be able to use them until you rebuild it.

Type Two: The player constructs certain buildings (very occasionally a unit, but the line between this and mere special abilities blurs here), which either directly grant the power, or grant it in addition to their other functions. These usually have a monetary cost associated with them, so you'll probably need more vespene gas if you use it too much.

Type Three: Stuff that doesn't fit in the above categories. These might be mission specific off-screen supports, or they might just be an innate part of the game, not tied to anything specific.

The effects of the Support Powers will vary wildly depending on which one you're using. Generally speaking, you can get a Status Buff, additional reinforcements (bypassing the normal "build time"), unlocking new units for use, or a damage dealing attack of some kind (ranging from air-strikes to superweapons). This is by no means an exhaustive list.

Examples of Support Power include:

Type One examples

Command & Conquer: Generals is possibly the Ur Example of Type One, but is certainly the Trope Codifier. In Generals, they are referred to as "General Powers", in Red Alert 3 they are known as "Top Secret Protocols". They do not have any monetary cost in both cases.
- Some missions also have Type 3, giving you access to support powers without the normal requirements or even entirely unique powers related to the plot.
The Lord of the Rings: Battle For Middle Earth uses the same system as the Generals example above. They were made by the same developers and on the same engine, so this is unsurprising. They are referred to as "Ring Powers".
Company of Heroes has these, referred to as "Doctrinal abilities", but they all have a monetary cost associated with them. The abilities you can select from are determined by your choice of "Doctrine" at the start of each match.
In Armor Games' Warfare 1917, the player can call for mortar, artillery, gas and armor-piercing shell attacks against enemy targets. Clicking on other icons summons reinforcements.
In Valkyria Chronicles, the protagonist is able to give orders calling for Sniper, Mortar and Artillery support on the field, costing you command points you otherwise use to move units.
In Age of Empires III, every nation has a Home City. In game, once you earn enough XP (gained by destroying buildings or units, building buildings or units, or just a small trickle) you can choose and send a shipment from your home city. What you get can vary from resources to units to upgrading your buildings.
Shattered Union player gains either good or evil points based on how much damage he did during battle. These unlock special powers, such as field repairs or nuke.

Type Two examples

Command & Conquer, Red Alert, RA2, YR, C&C3 had these. They usually came in the form of a dedicated building that provides it early on in the series life, but in C&C3 they mostly secondary functions of buildings necessary to climb your Tech Tree.
- For instance, building an Airfield in RA1 would allow the Soviets to send a spy plane to reveal parts of the map, or drop paratroopers or Parabombs. Plus there's the Superweapons in each game, available after building the last building on the techtree.
  - Aside from the superweapons, the second game only had the Paradrop ability gained from capturing an airfield (the US airfield gives one that drops more soldiers and doesn't stack with the other, allowing you to use both separately). Yuri's Revenge provided the Spy Plane to the Soviet Radar Dish and the Force Shield (makes all buildings in a large area invulnerable but shuts off all base power) for all Battle Labs.
Dune 2 has the "Fremen attack", which makes Fremen appear and charge at a specific target. You get it from building a Palace.
Dawn of War: Dark Crusade has several of these; the Space Marines have a satellite relay building that calls in Orbital Bombardment, but the Tau "Air Caste Strike" is granted by a unit, the Ethereal.
- Orbital Bombardment needs a unit to call it too: the Force Commander.
- Once the Orbital Relay building is complete, you can use it to deploy Space Marines and Dreadnoughts directly onto the battlefield instead of having them ferried to the relevant production structure via air.
The Terrans in StarCraft has several types of these, most notably the ability to reveal any part of the map on command, and another which allowed you to use nuclear warfare to take big chunks out of an enemy base.
In SWINE, if you have Strategic Points left over which you did not spend before the mission, you can use it to buy additional units (which are airlifted in by a helicopter) or call in bombers via your command car to launch airstrikes against specific targets.

Type Three examples

Command and Conquer series comes up again. There are too many examples of mission specific off-map support powers being granted to name them all. These go all the way back to the original, where you could call in A10 Thunderbolt strikes after you eliminated all enemy SAM sites in singleplayer missions (well actually, when you eliminated each enemy SAM site once).
Avalon Hill's Squad Leader had OBA (Off Board Artillery), which allowed a player to call down an artillery strike from units not on the board.
The old M1 Tank Platoon computer game had player-directed air strikes and artillery barrages.
Rise of Nations and Rise of Legends, in which each race's "National Power" is unlocked (and strengthened) solely by research topics. Research is integral to the GUI, so they can't be taken away from you.
- Also, the world campaign maps, being based on the Risk tabletop game, have Support Powers in the form of cards that can be played before every battle.
The various god powers in Age of Mythology fall under this. One can trigger these at any time to give their side a bit of a boost in battle, ranging from creating a building that heals or protects your troops, increasing the attack or defense powers of your troops, or calling in natural disasters like earthquakes, tornados, or freaking meteors to destroy the enemy's base.
- These are limited to one per "god", i.e. one per Age (except for the Atlanteans, who get less dramatic powers which can be used several times with a recharge timer).
- There are a few economical god powers as well, such as rain or growing a small forest.
In League of Legends, in which you play a "Summoner" controlling a champion for use as an avatar, each player gets two slots for these powers and has to choose which of about 10 spells s/he is going to bring. They range from "Immediate champion healing" to "Back from the Dead" to "Shield all buildings" to "Kill It with Fire," and many of them can only be deployed in a certain range around your champion.
Not an RTS, but in Super Robot Wars OG Saga: Endless Frontier, the characters stuck in your back row once you've exceeded Arbitrary Headcount Limit can do this. (To say nothing of the deep pockets you get for the Party in My Pocket come the sequel, where rotating back-row support goes hand-in-hand with a separate tier of pure support characters.)
In Super Robot Wars W, units could have Support Request on top of their Support Attack (Friendly adjacent unit gets to make a followup attack) and Support Defense (Friendly adjacent unit can Take The Bullet), which allowed them to call a Support Attack or Defense from a unit left in reserve.
The "Tactical Aids" in World in Conflict are essentially Type 3, though their costs vary depending on your role in multiplayer. They also have a recharge timer and don't come into effect as fast as in most other games (except for the scan, which is immediate).
- As a matter of fact, unit deployment could be considered as a support power aswell since the training etc take place offscreen and the troops are then flown in by plane (which by itself runs on a timer, both for airdropping the units and again to return to base).
The StarCraft II campaign has different kinds of those. On many missions, your Mission Control reveals portions of the map for you, usually those containing objectives. Certain types of units and buildings are not built at your base directly but arrive via "drop pods" from your Cool Starship—this includes all mercenary units, as well as, possibly, supply depots and barracks units depending on how you spend your protoss research points.
Achron's various time-manipulating abilities. They're so integrated into the gameplay mechanics and interface that it's easy to forget they are even support powers.