In late 1993, 2nd edition rulebook was published under the direction of Andy Chambers and with it introduced orks and rules that would support bigger battles and more models. Plastic models started to enter months after the 2nd edition rulebook, and new armies like the imperial guard and eldar growed into larger armies. It should be noted that in 1994 many races got thier own rulebooks known as a codex. Each codex has supplimentary rules and background as well as hobby articles on the specific race. Such an example is a codex for the space marines, coming with rules for each model, and wargear that adapted to the main rulebook. This alone started to gather many more gamers and eventually became a hit.
Then in 1998, the third edition was released. The rules growed even larger supporting bigger battles and rule balancing for armies. It came in a box with plastic space marines and the newly introduced dark eldar. Since 3rd edition contained a lot of rule changes all the army codexes were revamped to be used for the 3rd edition rulebook. At this time there were both pewter and plastic models and a growing popularity of players. Since the 3rd edition's release, there has been a cityfight rulebook released to allow players to fight in urban enviroments and creating a larger capacity in the hobby. Also, 2 new races were added in later years known as the Tau, and Necrons.
Then in 2004 came forth edition, which as of 2008 remains the current rulebook used. Battle for macragge was a supplementary release for the fourth edition including new tyranid models and spaces marines. This set also comes with a plastic crashed aircraft. The 4th edition rulebook is also inside the box, but a smaller soft cover version that has rules only rather than the hobby indexes and background story pages. After the release of 4th edition, the tyranids and space marines got new codexes as well as new models. In 2006 Gamesworkshop launched a campaign for Warhammer 40k with the release of a new supplementary book called cities of death. It is basically a update from Cityfight but makes urban warfare more simple to play and with it came plastic building kits to allow hobbyists to create there own style buildings and terrain. The Campaign was called medusaV which took place on a fictional world where all the races would fight for the planet in participating gaming centers. At the end, the space marines won the campaign. In late 2007, a new rulebook for 4th edition was released called Apocalypse. Apocalypse allows players to have very large battles ranging from hundreds of units and larger vehicles known as titans. Apocalypse is a very expensive portion to be in and requires large armies to play. Gamesworkshop released several plastic sets containing many models for a price that allowed players to get started. Forgeworld, a Sister company to Gamesworkshop produces high quality resin kits to assemble titans and other types of units. They have been a large supporter in apocalypse however since they are based in the united kingdom, the models can cost as much as 700 - 1,000 United States Dollars. Gamesworkshop made the Baneblade into a plastic kit, a large tank with many weapons mounted on it and perhaps a popular model for the Imperial Guard army. This costs 95 USD compared to Forgeworld's 280 Dollar kit.