After the mainstream success of the genre, stealth elements became increasingly incorporated into a wide range of video games, with numerous action games using stealth elements in some way or another. In 2002, the first installment of the Tom Clancy licensed "Splinter Cell" series was released, which attempted to add more realism to the stealth genre both in terms of graphics and in-game equipment. If the player is discovered in "Splinter Cell", the guards will often raise a general alarm which can cause a difficulty spike or even result in automatic mission failure. Clint Hocking, who worked as a level designer for "Splinter Cell", noted that this mechanic was in place at this point because the gameplay developers could not easily implement alternative player actions in the case of such detection; for example, on detection, a real agent may react by subduing the agent that found them, but this was not possible to program in at this point in time. Hocking recognized this would be frustrating to the player and would remain an issue with stealth games for about a decade. In addition, "Splinter Cell" was notable for its state of the art graphics, including dynamic lighting and shadows. Like "Thief", Splinter Cell featured a visibility meter which determined how much light was falling on the character. These effects not only contributed to the atmosphere of the game, but dynamically affected in which areas the player could hide. The 2004 sequel, "", added a multiplayer component to the stealth genre.