Explain the main differences between 'Versus' and 'Realism Versus' game modes in Left 4 Dead 2, including their objectives, key rule changes, and any specific requirements to play them. Provide details on how 'Realism Versus' impacts Survivor gameplay.
Navigate to the 'Gameplay Modes' page on the Left 4 Dead Wiki. Locate and review the sections for 'Versus' and 'Realism Versus' modes. Identify the main objectives and scoring for 'Versus' mode. Identify the main rules and how 'Realism Versus' differs from standard 'Versus' mode. Note any specific 'Realism' rules applied in 'Realism Versus' that affect Survivors. Determine any specific requirements, such as DLC, for playing 'Realism Versus' mode. Synthesize the gathered information to clearly explain the differences and requirements.
State that 'Versus' is a competitive mode where two teams alternate playing as Survivors and Infected, with Survivors earning points based on progression and reaching the safe room. Explain that 'Realism Versus' combines 'Versus' rules with 'Realism' rules, making it harder for Survivors. List specific 'Realism' rules applied in 'Realism Versus': lack of Survivor glows and instant Witch kills. Mention that 'Realism Versus' originated as a 'Mutation' and became a permanent game mode due to community feedback. State that 'The Passing' DLC is required to play 'Realism Versus'. Do not mention any Xbox Live requirement for either 'Versus' or 'Realism Versus' unless explicitly stated on the 'Gameplay Modes' page for that specific mode.