We first see Dharmadurai(Rajnikanth) as a loner, rescuing a young couple Balu and Ishwarya from the clutches of the goondas following them. Ishwarya is the daughter of Ramadurai(Saranraj) and has eloped with the blessings of her mother (Vaishnavi). It is her father's goondas who are after her now. Her father and her uncle Rajadurai('Nizhalgal' Ravi) show up, only to beat a hasty retreat when they realise who Ishwarya is with. Dharmadurai's wife(Gouthami) then tells them his story. Rajadurai and Ramadurai are none other than his brothers. He had showered love and affection on them and given them money against the wishes of his father(Madhu). But they had gotten involved in illegal activities and become rich by doublecrossing their own boss. Dharmadurai took the blame when they killed one of the villains and when he was in jail, his son was killed. He has been living in the jungle since coming out. When the villains capture Rajadurai and Ramadurai, their wives request Dharmadurai to rescue them. The portions where Rajnikanth helps his brothers play like Padikkaadhavan in a village setting with Rajni helping them out with money and dreaming of them reaching great heights. Rajni's antics with Gouthami and a couple of funny incidents help pass these portions entertainingly. Most Rajni movies have one long comedy sequence (the sequence where Senthil and Rajni go to fix up an alliance for Senthil, in Padaiyappa or the butterfly-catching sequence in Yejamaan) which is usually targeted at the kids. Here there is a lengthy chase involving him and 'Bayilvaan' Ranganathan along with a crab, a dog and a camouflaged trap on the ground. The 'kabadi' scene also raises some chuckles. Gouthami was a lucky charm for Rajnikanth with all their movies being hits. They exhibit good chemistry and it is quite evident here too, like in the scene where she dresses up like an old lady.
Such sequences are interlaced with instances of his brothers taking advantage of his naievity while his father warns him against trusting them. His troubles increase in intensity and losing his son turns out to be last straw. The scene where he thrashes his brothers after returning from jail is emotional and his resolve never to speak again is more effective than a longwinded, moralistic dialog would have been. The climax is quite lengthy, beginning in the villain's den and ending with Rajni saving his brothers when they are dangling from the the window of a high-rise hospital. Rajni's superhuman abilities are also on show with his using a bottle, a lighter and some acid to remove a bullet lodged in his arm!
As in most Rajni movies, a tired and familiar story is made watchable only because of Rajni himself. He melts our hearts when pledging the house to get his brothers money and later when he visits their palatial mansion and wants to be reassured repeatedly that the money was earned legitimately. The serious and funny scenes are mixed well like when Rajnikanth visits Vaishnavi's house after Saranraj has raped her. He evokes laughs by dressing up as a wealthy man before turning serious when appealing to Vaishnavi to withdraw the case. Senthil is wasted as Gouthami's father in a role that requires no comic talent. Madhu plays the role of the wordlywise father well.
Ilaiyaraja has an average soundtrack though understandably, the songs were pretty popular solely on account of appearing in a Rajnikanth movie. Sandhaikku Vandha... and Onnu Rendu... are the duets while Annan Enna... and Aanenna Pennennaa... are the usual philosophical songs. Maasi Maasam... is the top number and is both catchy and melodious though picturised quite steamily considering that Rajni movies typically are targeted at family viewing.
Though containing many elements that would fit into regular tamil movies, Dharmadurai is still a Rajnikanth movie at heart. It will please his fans though non-fans might have a more difficult time liking it.