Work Together
Work together, combining your attacks instead of merely minor annoyances by a single Special Infected attacking one after another.
Boomers and Spitters can hit their targets more accurately when a Survivor has been pounced on by a Hunter, charged by a Charger, or pulled by a Smoker.
Use The Environment
Wide-open spaces are the safest areas for Survivors. Save your attacks for tighter locations such as hallways, interior rooms, and around corners.
Long narrow hallways or stairways are what the Charger’s limited brain capacity deems an optimal attack point. Wait for all the Survivors to be in line and then round the corner to Charge.
Spitters can stay up on rooftops, out of reach, and continue to pester Survivors.
Maximise The Tank
When a Tank spawns, Infected brethren should stage their attacks when Survivors are all preoccupied with the gigantic, pink, lumbering entity.
Players who control the Tank should always look for objects that they can strike, since anything that hits a Survivor causes instant incapacitation.
Tanks can throw concrete at Survivors to ease their aggression meter. They can also attack and then retreat to wait for Infected brethren to respawn, as long as they can throw or attack before the meter runs out.
Lurking & Waiting
Special Infected should lurk in areas humans can’t reach, using the “claw pathways” to scale to rooftops, balconies, high ledges, and other ambush spots.
You should also make the most of other terrifying combat situations: Stand near Witches or cars with alarms to entice Survivors to shoot at you and wake a Witch or raise an alarm. Another optimal point to attack is during a Horde swarm.
Targeting
Choose the Survivor away from the pack, or the one with the lowest health, or one that’s already incapacitated. One dead Survivor is usually better than four wounded ones!