Read the mount line
The mount list on a frame page is a structural limit, not a recommendation to fill every slot. Compare it with the weapon sizes and license options available to the pilot.
Mounts shape the loadout.
A frame’s mount configuration defines which weapon sizes and combinations it can carry. It is one of the quickest ways to see how a chassis wants to fight.
Weapon size and type
Weapons have a size, a type and a damage profile. Their tags add rules that affect how they work. Review the full entry in the book when resolving a specific interaction.
Systems are another layer
Mech systems use system points rather than weapon mounts. They can add defenses, mobility, sensors or other capabilities, so reserve capacity for the tools that support your mission plan.
These editorial notes paraphrase concepts from the free player-facing LANCER Core Rulebook. They omit exceptions and full mechanics; the published book and your GM are authoritative.