The graha behind the word Manglik
Indian match-talk reduced Mars to a dosha in a few houses from the lagna. That is one face of Mangala, and it is not the whole graha.
Mars also describes energy, protection, sport, tools, land, younger brothers and sisters, and the will to act when a situation will not wait. A well-placed Mars can be the courage to operate, to compete, to hold a boundary. A troubled Mars can be the argument that never ends, or heat in the body with nowhere useful to go. The kundli writes which.
Sign, house, and what Mars rules
Mars in Aries or Scorpio is in a sign it owns. In Cancer it is in fall, and the heat sits in a watery mind.
Those are textbook facts. The house from the lagna still decides the subject: first house, the body and the manner; third, courage and siblings; sixth, conflict and service; eighth, sudden change; tenth, visible work. What Mars rules from your lagna matters as much as where it sits. For some rising signs Mars owns kendras. For others it owns more difficult houses. That is why two people with Mars in the same sign do not live the same Mars.
When Mars runs the years
A Mars mahadasha or antardasha often makes decisions, disputes, moves, and physical effort more important. Surgery, property, and competition show up in the questions people bring.
The result still depends on the Moon, the lagna, and whether Mars is running with help or under pressure from Saturn, Rahu, or a weak lord. Timing without the natal Mars is a story without an address.
Ask about drive, land, or a fight
You do not need to identify Mars before you ask. Questions about anger, protection, a brother, a plot of land, or work that needs nerve will bring Mangala into the reading.
Bring date, time, and place of birth. The main Mars article in the current library takes houses, dasha, and matching fears in more detail.
