Lucy is a mage and the main female character of Fairy Tail, joining at the start of the main story line. Lucy's member stamp is located on the back of her right hand.
At the beginning of the series, Lucy is an independent novice mage searching for a mage guild to join, particularly interested in Fairy Tail, which she claims as the strongest mage guild. Though she tells Happy she considered joining Fairy Tail's rival guild, Phantom Lord, due to their similar outrageous nature and personality, she is content with her decision of joining Fairy Tail. After being rescued by Natsu from the slave ship, she is invited to join the guild. Once joining Fairy Tail, Lucy becomes a member of Natsu's team.
Lucy is one of the saner and more stable members of Fairy Tail, having common sense that other members of the guild seem to lack. She consistently points out Natsu's and others' idiocy. Lucy is also very confident in her appearance and sexiness, exuding a certain amount of vanity. Despite this superficial attitude, Lucy is passionate for literature and is in the process of writing her own novel about her adventures with Fairy Tail. She is a member of the Heartfilia family, one of the richest and most influential conglomerate families in the country of Fiore. However, due to her estranged relationship with her father and the death of her mother, she left home to follow her own path.
It should also be noted that she was the only other person who had ever shut Gray and Natsu up without beating them up first. Natsu and Gray seem a little scared of her when she's under the weather, even if Lucy's magic is not as strong as theirs and can't force them into submission like Erza.
Lucy practices Stellar Spirit magic, a skill which allows her to summon spirits from another world using Keys of the Gates. Her Stellar Spirits have varying levels of power, with different ones suited for different tasks. For example, Aquarius can control water, while Taurus has enormous strength. Along with her keys, she also carries a whip, which she is proficient with. Lucy explains to Natsu that Stellar Spirit mages have the potential to obtain extremely rare Gold Keys, which open the gates of the "Ecliptic Zodiac", and common, store-bought Silver keys. Each gold key has the Zodiac symbol of the one it is used to summon on it. According to Lucy, while there is a large number of silver keys, there are only 12 gold keys. Thus far in the series, Lucy has obtained 10 Gold Keys and 4 Silver Keys. She also summoned all of her Gold keys (5 of them at the time) and Plue at once, although it only lasted a few seconds, it showed her to be very powerful. Loki's previous owner was a very powerful mage, yet she could not summon more than one at a time.