The Magicans’ Guild by Trudi Canavan (The Black Magician 1)

It is the day of the annual Purge. The Kyralia City Guards and the Magician Guild clean the city behind the walls from ‘dwells’, unwanted poors. The street urchin throws itching powder on the guards in revenge, but they can’t reach the magicians protected behind their protective barrier. Until Sonea a young ‘dwell’ hurls a rock through their barrier and hurt the magician Lord Fergun.

By law no magicians are allowed outside the Guild. Fearing a rogue magician the Guild begin searching for Sonea in the slums. Sonea evade capture with the help of Cery, her urchin friend. She strikes a bargain with the Thieves to keep her hidden in exchange for their own rogue magician. Soneas magic gets increasingly more uncontrolled. In an attempt to learn control she and Cery sneaks onto the Guild grounds to watch the novices train. There she observes a black robed magician performing some sort of draining magic on a servant.

All her efforts of control fails and she is eventually captured. Her distrust of the Guild is founded on the way they treat her and her follow dwells. Lord Rothen and the sinister Lord Fergun both compete for her guardianship. Lord Fergun inprison her friend Cery under the school and blackmail Sonea to name him her guardian. His plan is ultimately revealed.

I like the characters and the world Trudi Canavan has made.