_special2 or buildspecial = Lay a landmine.
buildspecial2 or senmine = Lay a sensormine.
detspecial = Detonate your existing landmine(s) and sensormine(s).
See "ntf_help_vars" for Landmine player VARS.

saberdisc or shuriken = Throw your saberdisc!

marker, mortar, and detmarker = Mortar Marker commands. See "ntf_help_mortar"

Landmines must be detonated by hand - they do not explode on contact.

Sensormines must also be detonated by hand, but they will inform you when an
enemy is nearby. They also emit an audible ping when an enemy approaches.

Both types of mines will auto-detonate after 2 minutes.

Touch an inert multigun to upgrade it to a Grenade Launcher.