छापा या धावा एक प्रकार की सैनिक रणनीति है जिसका एक निश्चित उद्देश्य होता है। किन्तु समान्यतः इसका उद्देश्य किसी भूभाग पर अधिकार जमाना नहीं होता, बल्कि कार्यवाही को शीघ्र समाप्त करके शत्रु द्वारा जबाबी कार्यवाही श्रु करने के पहले ही अपने पूर्व स्थिति में वापस आ जाना होता है।

Raiding, also known as depredation, is a military tactic or operational warfare "smash and grab" mission which has a specific purpose. Raiders do not capture and hold a location, but quickly retreat to a previous defended position before enemy forces can respond in a coordinated manner or formulate a counter-attack. Raiders must travel swiftly and are generally too lightly equipped and supported to be able to hold ground. A raiding group may consist of combatants specially trained in this tactic, such as commandos, or as a special mission assigned to any regular troops. Raids are often a standard tactic in irregular warfare, employed by warriors, guerrilla fighters or other irregular military forces. Some raids are large, for example the Sullivan Expedition.