The "Clan 'Mech Pak" is comprised of new BattleMechs and technology compatible with "MechWarrior 4: Vengeance" and the "MechWarrior 4: Black Knight" expansion. The four new 'Mechs featured are:

• Masakari - Easily identified by its squat torso, jutting head, and broad chest, this 'Mech has become notorious for its deadly accuracy 
• Kodiak - A large, fast-moving Assault 'Mech that carries impressive medium-range firepower
• Arctic Wolf - Loaded with SRMs, this BattleMech can rapidly close with an enemy and shower it with more than 40 missiles
• Cauldron-Born - Named for the unstoppable zombies of Irish myth, this 'Mech can take immense damage and remain operational 

This Pak also brings into play a new weapon and sensor package:

• Streak MRM - A new, homing version of the Medium Range Missile, made possible by Clan technology
• Enhanced Optics - This component of the new Clan 'Mechs gives the MechWarrior a larger field of view when zooming in on distant targets 

Lastly, the "Clan 'Mech Pak" features an all new multi-player map, the Factory in which 'Mechs battle it out amid the ruins of a huge factory on Solaris.