Construction of the Warhammer BattleMech, which was designed primarily as an assault 'Mech, began in 2515 and continued up until after the fall of the Star League. The original requisition by General Sternson to StarCorp Industries called for "a mobile 'Mech with enough firepower to destroy or severely damage any 'Mech of the same weight class or lower". StarCorp's answer was the Warhammer. There were several different production runs of the 'Mech, including the Class 6D and the Class 6K. In the current era, several modified versions have also been developed within the Successor States.

The MAD-3R Marauder is considered one of the most effective BattleMechs in existence. When first built by GM in the early 2600s, its unique design was intended as the precursor of a new generation of 'Mechs. With the fall of Star League, however, the other 'Mechs in the Marauder series remained on the drawing board. Although the Marauder is a common 'Mech today, many of its design elements remain unique.

Even during the Star League era, the number of manufacturers capable of building a 'Mech like the BLR-1G was limited. After they won the bid to construct the 'Mech, Hollis Industries began production of the BattleMaster in 2830. Designed to be the largest and the most powerful 'Mech ever fielded by the Star League armies, the BLR-1G filled the bill.
The 'Mech's sheer size required special manufacturing facilities, which meant that Hollis could build the BattleMaster on only a few planets. The cost and materials for the 'Mech also limited production somewhat.

The VTR 9B Victor was originally built under a defense contract with the Star League in 2510. Defined as a heavy BattleMech, it was used as a strong support 'Mech with jump capabilities. Earlier models carried a sophisticated array of anti-infantry weaponry systems, later discarded due to the overheating problems common for a heavily armed 'Mech. Also technicians felt that this heavy-support 'Mech would not engage infantry, and so the flamer and machine gun systems were removed. The Victor was originally outfitted with a Standus 20 tracking system, but it was removed from all but the first-run prototypes due to its tendency to project targets that did not exist.
HildCo Interplanetary produced the 'Mech out of three plants whose facilities were destroyed during the First Succession War. Most of the firm's records fell into the hands of House Kurita, however. Thus, the total number of Victors produced has been determined to be nearly 1000. Many were lost during Kerensky's exodus from the Star League, and still more were lost during the First Succession War.

The ARC-2R Archer is one of the best-known designs still in use today. First produced in 2474, the Archer quickly earned respect and popularity among BattleMech regiments that was unequalled by any other type. Star League records show that nearly 100,000 Archers were constructed before the beginning of the Succession Wars. Most of these have now been destroyed or lost to spare parts depots. However, some production of the many Archer variants continues to this day in most of the Successor States.
The Archer was designed initially as a heavy-hitting assault 'Mech, able to pound defending units at long range as it approached. Over the centuries, it has also been used in a variety of other roles, ranging from city-busting to indirect fire support.

The first Rifleman was built for Star League by Kallon Industries in 2505. Designed as a medium fire-support vehicle, this early model was lighter and less heavily armored than the current version, and mounted Kallon Class C laser cannon. Chronic overheating forced the addition of more heat sinks and the replacement of the old lasers with more efficient Magna IIs and IIIs.