’Mech Manual: Adder Prime

The Adder OmniMech was developed by Clan Star Adder in 3010 in preparation for the invasion of the Inner Sphere. While not as fast as many other light ’Mechs, it is capable of carrying a large amount of weaponry. Its Prime configuration makes good use of that pod space in order to carry two ER PPCs that give it a strong, long-range punch.

The Adder had spread to all of the Clans by the beginning of the Clan Invasion era. When Inner Sphere forces first encountered it, they gave the OmniMech the Puma designation. The design has continued to be widely used into the Dark Ages era.

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  • Try to engage targets at a range of about 14 hexes
  • Alternate between firing one and two of your ER PPCs
  • Be careful about rough terrain since you lack jump jets

Adder Prime

  • Role: Sniper
  • Tech Base: Clan (3010)
  • Chassis: 35 tons (Endo Steel)
  • Movement: 6 / 9, XL
  • Armor: 115 (Ferro Fibrous)
  • Heat Sinks: 11 (22)
  • Weapons:
    • ER PPC × 2
    • Flamer
  • Equipment:
    • Targeting Computer
  • Design Quirks:
    • Narrow/Low Profile
    • No Torso Twist
  • Cost: 7,021,688 C-Bills
  • Battle Value: 2,083


The Adder has below average mobility for a light ’Mech. It has 6 MP walking and 9 MP running which is just below average for its weight class, but the lack of jump jets means that it has far less mobility in rough terrain. When running in clear terrain, it can achieve a +3 target movement modifier.


The Adder is tough for its weight class. It carries 97% of the maximum armor for a 35-ton chassis with all locations other than its legs maxed out on protection. The Narrow/Low Profile quirk then lets that armor last longer by halving the damage from some hits. The Clan XL engine means that the Adder is more vulnerable to engine damage, but it can still survive the loss of one of its side torso locations.


The Prime configuration is equipped with two ER PPCs paired to a targeting computer. That gives the Adder the ability to deal up to 30 damage out to a range of 23 hexes. The targeting computer allows for that weapon fire to be more accurate than normal and makes the Adder Prime a very capable sniper.

Maximum and Expected Damage

In general, a MechWarrior will want to maintain a range of about 14 hexes in order to be able to fire their PPCs with good accuracy while staying at longer ranges for return fire from targets with shorter-range weapons. The exception to that is when a MechWarrior wants to use the targeting computer to make an aimed shot. In that case, they should close to within 7 hexes to improve the chance of actually hitting with the aimed shot.

The Adder Prime’s PPCs are mounted in its arms to let it maintain good firing arcs despite its No Torso Twist quirk. In addition to being able to fire one PPC in to either side arc, it can flip its arms in order to fire both behind it.

Maximum Damage for Firing Arcs

None of the Adder Prime’s weapons consume ammunition.

Heat Management

The Prime configuration is limited by the heat of its weapon systems. Firing both of the ER PPCs generates 30 points of heat and its 11 double heat sinks can only dissipate 22 points. That leaves the Adder between 8 and 10 heat buildup on any round in which it uses its full firepower. Firing just one PPC on a following round then only allows for reducing that by 7 to 9 points. That means that even holding fire with one PPC every other round is not quite sufficient to prevent it from gradually getting hotter and hotter during a battle. In order to fully cool off, a MechWarrior will occasionally need to not fire any weapons.

Heat-Adjusted Maximum and Expected Damage


The Adder Prime should avoid brawls. It lacks lower arms and fists, so its punches are inaccurate and only deal 2 damage. Kicking is a better option with a potential 7 damage, but a MechWarrior in an Adder Prime should try to stay out of reach and make use of the long range of its weapons.

OmniMech Chassis

The weapons and equipment of the Adder can be re-configured between missions. It can carry 16 tons of equipment in addition to its built-in flamer. It has a good number of available critical slots in both its side torsos and arms. One of the Prime configuration’s heat sinks is pod mounted.

Capacity16.0 tons
Center Torsonone
Right Torso5 slots
Left Torso5 slots
Right Arm7-9 slots
Left Arm7-9 slots
Right Legnone
Left Legnone

The Adder Prime is able to serve as a transport for a unit of battle armor. Thanks to the location of its weapons, it does not lose any firepower when carrying up to five battle armor. Its combat role though can make it a poor choice for mechanized battle armor though because it wants to stay at a longer range from its targets rather than closing to a good short range drop off location.

Cost & Upkeep

The Adder is an expensive Clan frontline OmniMech. It makes use of an XL engine, ferro-fibrous armor, and endo steel. Because it only has energy weapons, there is no cost for ammunition reloads during a campaign.

When using the Warchest Point system, these are the expected costs for the Adder Prime:

ActionClan CostInner Sphere Cost
Purchase700 SP1,400 SP
Armor Repair35 SP70 SP
Structure Repair70 SP140 SP
Reconfigure9 SP18 SP


A new plastic miniature for the Adder is included in the Clan Invasion box.


More ’Mech Manuals

By Scott Boehmer

A game enthusiast and software engineer.

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