Mars in 3rd house. 

So, lets see what Mars can do in 3rd house without any conjunction or aspect from any other planet. 1st lets see what these 2 things represent -

Mars represents our will power, courage, ability to take actions, aggressive nature, anger, our fighting ability, brother, male friends, a boy friend for a girl, a soldier, an athlete and real estate etc. 

3rd house - It is house of your communication skills, neighbours, short distance travels, younger siblings, marketing, announcements, collecting information, hobbies and skills, self-efforts, business, courage etc.

So Mars, the planet of courage is now coming into the house of courage. What will it make? Obviously, a very courageous person. These are highly courageous people who can take any risk in given situation. They can be very dominating with their communication and speech. Even their writing may be thought provoking. As 3rd house also represents communications and Mars represents hands, they are very good with their written communications. They can be very aggressive in their writing. They can motivate people with their blogs or articles. They write very aggressively, that's why they can become very good lawyers too. As 3rd house is Upachaya House, most of these results can be seen in 30s,. 

From 3rd house, Mars aspects the 6th house of disputes and litigation, another reason for them to become a lawyer, communications are impacting disputes and litigation. This is also a great position for having a peaceful married life because this person will take pro-active measures to prevent conflicts. 

Mars next aspect goes to 9th house of teachings of Guru and it can lead to dominating struggle between them and their Gurus. 

Mars next aspect goes to 10th house, and same aggression goes against the authority of father and they try to get the authority from father or career. But overall, a very good position for a strong willed person who can do anything to achieve on his own. 

Hope this helps. Thanks,

Swami Premanand Bharti