Natural Selection

Natural Selection (NS) is a mod for the video game Half-Life. Its concept is a mixture of the first-person shooter (FPS) and real-time strategy (RTS) game genres.

The game was created by Charlie "Flayra" Cleveland, who later founded the company Unknown Worlds Entertainment. Natural Selection v1 was first publicly released on Halloween 2002, and is presently at version 3.2. Production of Natural Selection 2 is underway.

The game features two teams: Kharaa (alien species) and Frontiersmen (human space marines). The visible Kharaa "units" are actually simply the spawn of the real Kharaa (aliens) which are microscopic life-forms according to the NS story line.

As of 2008, the game is one of the ten most played Half-Life modifications in terms of players, according to GameSpy.

Overview
Natural Selection is a hybrid FPS / RTS that pits Marines against Aliens ("the Kharaa"), played primarily in the first-person perspective, within the confines of large atmospheric maps of spaceships or space stations, which have been invaded by the Kharaa.

There are two game modes in Natural Selection: Classic and Combat.

Classic game mode
Classic is the original Natural Selection game, mixing FPS and RTS elements.

Distinctive Aspect: Marine Commander
Natural Selection was the first multiplayer, First-Person Shooter to incorporate a "Commander", whose view of the battlefield was essentially 2-D, from a strictly top-down perspective. One member of the marine team must enter the "command chair" to lead the team, and thus become the "Commander". From here, he can purchase upgrades, issue movement orders and drop supplies - all from an overhead perspective, as in many RTS games. The commander can also place buildings, although these are inactive until built by players in the field. The role is somewhat similar to the Intelligence Officer of Global Operations in that it is provided an overview of the map, though the ability to place objects and control is much more extensive. A similar 'commander' mode can also be seen in Battlefield 2 and the Empires modification for Half life 2.

Alien Team
The alien team has no defined leader, and so it must communicate and co-operate to ensure different roles are fulfilled as needed. There is only one "Builder Class", the Gorge which can be used to build a multitude of structures. Gorges can choose to build three different "upgrade" chambers: Movement, Defence, and Sensory, each providing three distinct abilities each alien can get. Gorges can also build Offence chambers which damage Marines from a distance, and resource towers. When a resource nozzle is capped, the resources gained are split evenly among all aliens. Each alien can choose how he wants to use his own personal reserve of resource points : building structures (as a gorge), or gestating into higher lifeforms. On death of the lifeform or structure, there is no refund on the resource points spent. Kharaa "Hive Sight" reveals teammates through the walls and structures of the map, this was originally their answer to the commander with his top-down overview of the game. However in later versions both teams have gained substantial advantage from the addition of a map hotkey. This overlays the whole level, showing teammates and friendly structures; plus enemies and structures currently in view of comrades, and areas under attack.

The aliens start with one active hive, randomly chosen from the 3 hive spots of the map. Active hives heal damaged aliens and respawn dead players. Marines initially spawn in a set location on the map, and after that spawn from Infantry Portals, which can be built in a set radius of the Command Chair. Healing and ammunition can be dropped by the commander in 'packs' (at a cost) or obtained free from an Armoury.

Goals and Victory Conditions
The teams compete for territory, and critically for the resources ('res') it offers. The currency for both sides, resources are obtained by building resource towers to tap the nozzles sited around the map. This is another area where the teams have a key difference - while marines draw on a common pool of resources, each alien accumulates a personal store. This further increases the requirement for teamwork on the alien side, to achieve the right balance of hives, lifeforms, resource towers and chambers.

The game ends when either all the Marines or Aliens are dead, and have no means to respawn. For the Frontiersmen (marine) side, this entails destroying all alien hives, ensuring no further alien players may respawn, and then hunting the rest down. For the Kharaa (alien) side, winning requires destroying all marine "Infantry Portals", ensuring that they do not respawn, and then eliminating the rest of the marines. Other possibilities exist such as destroying the command chair, or destroying all finished hives, and killing the whole alien team before the remaining hive is fully grown.

Duration and Balance Refinements
Game duration and game balance has been continually addressed by Unknown Worlds Entertainment throughout each of their releases with extensive changelogs describing these issues. In v1, games were slower and often measured in hours. One of the stated aims of v2 was to address this, by introducing a broad range of changes to abilities, structures, etc. In current releases (v3), a typical game lasts 5–15 minutes, but can run over an hour, with both sides vying for control over strategically important Hive Rooms and Resource Nodes.

Combat game mode
Combat is the team deathmatch, or beginner mode of NS. It was introduced in NS 3.0 to help new players learn how to play alien lifeforms in an easier environment.

Neither team can build structures, the marines do not have a commander, and aliens have only one hive. Each player has an individual experience meter, increased by killing enemies; dealing damage to the enemy hive/command chair or healing/repairing their own hive/command chair. When the experience meter reaches maximum, the player gains a level and it resets.

There have been various changes to the spawn system in the various betas to try and make matches more interesting and more winnable but also without making it such that a team that suffers a major loss of players can still come back. An admin configurable time limit (default 15 minutes) was introduced in beta 5 which remains in the final version. With the time limit, Marines are usually on the attacking side and Kharaa are on the defending side. Failure of the attacking side to win within the time limit results in a victory for the defending side.

Reception

 * GameSpy hailed Natural Selection as "possibly the most ambitious user-made modification ever brought to fruition. This multiplayer-only mod somehow manages to transform the aging Half-Life into a seemingly brand-new, atmospheric, and surprisingly deep action-strategy game, pitting hive-minded aliens against resourceful space marines," and "Natural Selection's innovations are too numerous to list, but the marine's "commander" mode deserves special mention. Playing as the marine commander, you can order and re-supply other marines in an RTS-style, top-down perspective."
 * FiringSquad : "The way all these details boil down in gameplay is simply amazing, and occasionally fascinating to just watch unfold," and "is probably one of the most creative and well thought out shooters we’ve played in a very long time."

Competitive Play
Traditionally clan play in Natural Selection comprises 6v6 gameplay - Aliens versus Marines. The objective of clan matches is the same as in public matches - to eliminate the opposing team. After one clan is successful, they then switch sides. If the score is 1-1 after two rounds, they generally accept a tie if in group play or play another set of rounds when playing a playoff game of a tournament.

Though never reaching the popularity of other Half-Life Mods such as Counter-Strike, Natural Selection has had a competitive community since its inception - one which still exists today, since the original release in 2002.

Previously North American clans competed in the Natural Selection division of the Cyberathlete Amateur League before it was shut down due to several factors, those being a lack of participating teams, mostly attributed to a rise in player's cheating, and poor leadership of League Officials. The remaining League community created the American Natural Selection League, which remained active until early 2008. European players formerly had several Cups and Leagues to compete in such as UGL, Clanbase, and Gamingorb, but now they play exclusively in the European Natural Selection League, with occasional single-day tournaments. Australia and New Zealand formerly had semi-frequent online tournaments run by the now defunct Ausns, and OGR, and then later NSPlayer.net, which also drew in teams from Asian countries such as Singapore and South Korea, but have since stopped due to lack of participating teams.

Natural Selection 2
Natural Selection 2 will be the sequel to Natural Selection. Natural Selection 2 started development using the Source Engine, however their development blog later announced that Unknown Worlds had moved to an unnamed proprietary engine. Natural Selection 2 will have the same basic gameplay as Natural Selection, but with new weapons and abilities. It will be released commercially on Steam. According to an interview with the Game Director, Charlie Cleveland (Flayra), the sequel will continue where the original left off and will feature environments that are dark and denser. Several gameplay modes only currently available as community-developed mods (such as Marines vs. Marines) will now become officially supported modes. Cleveland did not state any information as to when the game will be available, however there is currently a development blog in which players can monitor development progress. The first major possible new feature of Natural Selection 2 revealed so far is Dynamic Infestation, released in December 2006. The proposed feature would dynamically generate bacterial infestation based on what areas of the map the alien team controls.

The development team has announced that a technology release will be made available prior to the game's release to allow members of the community to develop maps for the game. They have announced their intentions to purchase the best community developed maps and to include these maps in the game upon release.

As of 27 May 2009, the game is available to pre-order from and the first teaser video showing in-game footage with the Onos is available here.

The alpha testing of Natural Selection 2 began on 26 July 2010.