Guerilla warfare

“a form of irregular warfare in which a small group of combatants such as paramilitary personnel, armed civilians, or irregulars use military tactics including ambushes, sabotage, raids, petty warfare, hit-and-run tactics, and mobility to fight a larger and less-mobile traditional military.” (related: asymmetric warfare; “Punch above your weight.”)

Gabriel Weinberg's Mental Models I Find Repeatedly Useful