In real-time strategy games, the term sidebar refers to a unique real-time strategy (RTS) control interface first used by Westwood Studios for its various RTS games, making its debut in Dune II: The Building of a Dynasty from 1992. As its name implies, the sidebar interface is a vertical bar display that is usually located on the right side of the game screen and serves a variety of functions, most notably the queing of buildings and units.
The sidebar is a unique command interface that takes the form of button-laden bar on the side of the game screen.
Command & Conquer games that make use of sidebars typically have them placed on the far right of the game screen. In most cases, the sidebar itself will have the following interface details starting from top to bottom:
- Credit count
- Minimap (if the radar building is present and powered) or faction logo
- Repair and sell buttons
- Building list
- Defensive building list (Red Alert 2 and onwards)
- Unit list (until Tiberian Sun: Firestorm)
- Infantry list (Red Alert 2 onwards)
- Vehicle list (Red Alert 2 onwards)
- Aircraft list (Tiberium Wars onwards)
- Navy list (Red Alert 3 and Uprising only)
- Power meter
In Tiberium Wars and newer titles, the sidebar system was expanded with a support power bar shown on the far left side of the screen, as well as a unit information box on the bottom right.
The various buttons on a queue will commonly display a unique building or unique unit, depending on which queue the button is listed under. Clicking a button will divert funds from a player's bank account, draining the funds until the building/unit is fully purchased.
Once a building is fully purchased, the player can select a place to put it on the game map, though the radius in which buildings can be placed is typically centered on a construction yard or its equivalent. Notable exceptions to this rule include buildings captured by engineers, which boast a small radius in which buildings can be placed. Once a buildings' location is selected, the building will instantly sprout up from the ground, adding its own abilities/attributes to a players' greater base.
The purchasing of game units differs slightly from the purchasing of buildings. Like with buildings, the clicking of a button on a unit queue will divert funds from a player's account until the unit's cost is fully paid. However, unlike buildings, units do not require placement on the battlefield once they are fully purchased. Instead, the unit will automatically emerge from a unit producing building, should the player have one constructed. If a player has more than one unit producing building that can produce the unit in question, the unit, and all other units from that queue, will emerge from that building at a faster rate than if there were fewer buildings like it. In other words, the more producing buildings a player has, the faster the units will be produced. The building in which units emerge is called a "primary building."
Building and unit production differ in another significant way. Whereas the construction of a building under a specific queue will render all other building buttons unusable until the building is finished, the selection of a unit for construction will not. Multiple units can be purchased at any time, even if another unit is under construction. Construction will then follow the order in which the unit types were selected; when all of the units of a specific type are purchased and deployed, the units of the next type will be deployed afterwards.
Above the building/unit queues are the repair/sell buttons. Repair buttons typically have a wrench symbol emblazoned on them, while the sell buttons have a dollar sign (in Red Alert 3, variations with the Russian ruble and the Japanese yen exist).
Selecting the repair button will change the game cursor from the standard pointer to the "repair" pointer. Afterwards, any friendly damaged building selected by the pointer will slowly repair over time, while at the same time diverting funds from a player's account for each hit point restored to that building. Buildings that are being repaired will display a wrench symbol above them until the building is fully repaired.
Next to the "repair" button is the "sell" button. The sell button, when selected, will change the standard pointer to the "sell" pointer, similar to the repair button. Any friendly building selected by the player will instantly de-construct, with a portion of its cost being refunded to the player's account.
At the top of the sidebar is the radar screen, a square display that serves a variety of functions. During campaign missions, the radar screen can serve as an in-game video screen, displaying character interactions and crucial story points that can’t be shown with the game engine alone. In all game modes, the radar screen serves to display all locations visited by units controlled by the player. Various items of interest, like resource deposits, topography, units, and buildings are all displayed here for the player to better coordinate his forces. Forces belonging to different armies, be it friendly, allied, and enemy, will often be color coded for better discrimination.
Radar screens are typically dependent on a radar building of some sort to be constructed by the player in order for them to work. When a radar building is not constructed or functional, the radar screen will deactivate, displaying the player's affiliated faction symbol instead. Once a radar building is restored, the screen will display radar again.
The power needs of a player's base are displayed on the far left side of the sidebar, commonly as a thin vertical meter. Power consumption is shown as a red series of lights rising up past a green/yellow series of lights. Should the red overtake the green/yellow, the base’s power needs will be exceeded, with new power supplies needing to be constructed/repaired in order for power to be restored. In the games between Tiberium Wars and Red Alert 3 Uprising, the power bar is either red or green (no yellow indicator), while in Tiberian Twilight, the coloring of the power meter is eliminated altogether and is replaced with a numeric gauge.
When a base loses power, unit and building construction will slow down significantly, sometimes coming to a complete halt depending on the game.
Pre-Command & Conquer
Although the sidebar is mostly known for its prominance in the Command & Conquer series, the gameplay feature is traced to Dune II: The Building of a Dynasty released in 1992.
The Dune II iteration of the sidebar was, in many ways, a "Mk. I" of the sidebars that were to come. Like future Westwood titles, the sidebar of Dune II was on the far right of the screen, had a radar display at its top, and building/unit selections. It also displayed the player's monetary account, which was composed of money garnered from gathering the Spice Melange.
Being a primitive early draft of the sidebar idea, the sidebar in Dune II lacked many of the nicities that would appear later in its evolution. Buildings and units could only be selected for construction by clicking on a specific construction building (e.g. a construction yard in the case of buildings), and a sizeable chunk of the bar was used to display unit information and buildings currently under construction. In addition, the selection of new buildings for construction required the player to open an entirely new menu for selection, an action which effectively paused the game.
These features would be abandoned in future iterations of the sidebar.
The original Command & Conquer built upon many of the pre-established gameplay mechanics from Dune II, the sidebar being one of them. The new version of the sidebar included most of the features that would remain constant through the series, such as a building and unit lists, as well as a power meter. Players no longer needed to select specific construction buildings to build specific structures/units. Instead, they simply needed those buildings to exist. This allowed for a much more streamlined and smoother gameplay experience that would set a standard for the RTS genre. Queueing was not possible for either buildings or units at this stage. The sidebar could be turned on and off at will.
These concepts would remain unchanged in the game's quasi-sequel, Red Alert. Built on the same engine as the original, the sidebar in Red Alert was identical to that of its predecessor.
The sidebar from Tiberian Sun was mostly similar to the previous iteration, with several updates. The options of building and training could now be viewable by scrolling the mouse wheel. A building queue was enabled for units of the same type, which means that a player could order up to 5 infantry units, vehicles and/or aircraft at the same time. This could be changed in the rules.ini file to a different value.
While Red Alert 2 used a heavily modified engine from Tiberian Sun, the sidebar mechanic was greatly expanded. It divided the building options to four tabs: buildings, defensive structures and support powers, infantry, and vehicles (with aircraft and naval units). Defensive structures could now be built independently from the regular structure "queue", and the default unit queue was raised from 5 to 30. On top of this, each queue could be quickly selected by using the Q, W, E, and R keys as hotkeys.
Although Command & Conquer: Generals replaced the sidebar with a bottom bar interface that was by then more prevalent in the genre, Tiberium Wars returned to the sidebar mechanic. The new sidebar design was a modernization of the Red Alert 2 iteration, featuring the same organization strategy and hotkey system. Two new tabs were added; one specifically dedicated to the production of aircraft, and another, located on the far left, displayed the number of selected units. In addition, the selected unit (type) had its information displayed in the bottom right corner of the screen. Support powers were shown at the left border of the screen, while movement and stance settings were located in the bottom left corner.
As each factory could produce structures/units independently, each construction option list was divided to queues belonging to specific factories in the order the factories were built in.
Unlike in previous games, where the bar constantly blocked the right side of the screen, even when most or all of its "buttons" were blank, the Tiberium Wars sidebar would only display as many buttons as a factory type could produce, with the exception being campaign missions where certain units or buildings showed an icon with the faction logo and a lock, due to the static nature of the new listing mechanism. The rest of the right end of the screen was transparent, unlike the previous games.
For the first time, the interface could be switched on and off, with the hotkey being assigned to the "End" key by default.
The Red Alert 3 sidebar was based largely similar to the one from Tiberium Wars, and added a seventh tab - the ship list. The build queue tabs in Red Alert 3 were strictly limited to nine units, while Uprising expanded the limit to twelve. Special scripts had to find other ways to make non-standard units buildable, such as the Tesla tank replacing a unit in a separate war factory owned by Anatoly Cherdenko during the mission The Stone-Faced Witnesses.
A new element was also introduced - the Threat Meter. It was an indicator of danger in which the player's units were found at a given moment, which would increase the speed of obtaining Security points. These points can then be used to unlock Top Secret Protocols, enabling the use of support powers or upgrading certain units.
In the Commander's Challenge mode in Uprising, the Threat Meter could also show a new "Red Alert button" if the meter was full. This power could only be used once per game, and would make all active units of the player elite and set the fund reserve to maximum, but would log the length of the game as if it were played for 100 hours as a penalty.
Command and Conquer series
- Command & Conquer
- Command & Conquer: The Covert Operations
- Command & Conquer: Gold
- Command & Conquer (PlayStation port)
- Command & Conquer (Nintendo 64 port)
- Command & Conquer: Red Alert
- Command & Conquer: Red Alert (PlayStation port)
- Command & Conquer: Red Alert: Counterstrike
- Command & Conquer: Red Alert: The Aftermath
- Command & Conquer: Red Alert: Retaliation
- Command & Conquer: Tiberian Sun
- Command & Conquer: Tiberian Sun: Firestorm
- Command & Conquer: Red Alert 2
- Command & Conquer: Red Alert 2: Yuri's Revenge
- Command & Conquer 3: Tiberium Wars
- Command & Conquer 3: Kane's Wrath
- Command & Conquer: Red Alert 3
- Command & Conquer: Red Alert 3: Uprising
- Command & Conquer: Red Alert 3: Commander's Challenge
Other Westwood Studios games
- Dune II: The Building of a Dynasty
- Dune 2000
- Dune 2000 (PlayStation port)
- Emperor: Battle for Dune
Many games would copy the system in the years following the release of Dune II, with most making a few small edits. The core mechanics, however, rarely changed. In later years, the bottom bar concept was more prevalent.
- WarCraft: Orcs & Humans (1994, Blizzard Entertainment)
- WarCraft II: Tides of Darkness (1995, Blizzard Entertainment)
- WarCraft II: Beyond the Dark Portal (1996, Cyberlore Studios)
- WarCraft II: Battle.net Edition (2000, Blizzard Entertainment)
- Krush, Kill, N' Destroy (1997, Beam Software)
- Krush Kill 'n Destroy Xtreme (1997, Beam Software)
- Seven Years War (1997, hq team)
- Dark Reign: The Future of War (1997, Auran Games)
- Dark Reign: Rise of the Shadowhand (1998, Auran Games)
- Total Annihilation (1997, Cavedog Entertainment)
- Krush, Kill, N' Destroy 2: Krossfire (1998, Beam Software)
- The Settlers III (1998, Blue Byte Software)
- The Settlers III: Mission CD (1999, Blue Byte Software)
- The Settlers III: Quest of the Amazons (1999, Blue Byte Software)
- Ancient Conquest: Quest for the Golden Fleece (1999, Megamedia Australia)
- Machines (1999, Charybdis Limited)
- Star Trek: New Worlds (1999, Binary Asylum / 14° East)
- Star Wars: Force Commander - alpha builds only (2000, LucasArts)
- Majesty: The Fantasy Kingdom Sim (2000, Cyberlore Studios)
- Majesty: The Northern Expansion (2001, Cyberlore Studios)
- Majesty: Gold HD (2012, Cyberlore Studios)
- The Settlers IV (2001, Blue Byte Software)
- The Settlers IV: Mission CD (2001, Blue Byte Software)
- The Settlers IV: The Trojans and the Elixir of Power (2001, Blue Byte Software)
- The Settlers IV: The New World (2002, Blue Byte Software)
- The Settlers IV: Community Pack (2003, Blue Byte Software)