Ratchet is a street-wise, wrench-swinging guy who always liked to get into an adventure without really thinking about the risks or odds. He made many sarcastic comments or jokes and could take things personally, but over the series of the games, Ratchet seemed more matured and serious. He enjoyed swinging down Zip-lines and using his Swingshot.
Ratchet, like many Lombaxes, is also known to have invented some items, some were more successful than others. These items included Stunderwear, for example.
In the first game, Ratchet was very selfish, arrogant, and self-absorbed and Clank had to talk him into helping other planets. Throughout the course of the game, however, he became more dedicated and serious to stopping Drek's plans. After that, he became a less selfish person, and a more likeable character. He became very selfless, and at the end of Deadlocked was willing to give up his life for all the captured heroes that he eventually saved. In A Crack in Time, Ratchet was seen as more of an intelligent, humble and serious character. This personality has also been seen in All 4 One, as he has shown a compassionate side as well.
Clank was a standard model 7.66 robot and ran on XP-88 sisterboards. While normally rather unimpressive, Clank's strength came from his highly modifiable body, his most common being converted to a backpack. He was fitted with the Heli-Pack, Thruster-Pack, Hydro-Pack and robo-wing upgrades.
He seemed to have some sort of device for shrinking devices in his torso. He got an ability to transform into a Giant Clank ultramech using an Ultra-Mech launch pad. He was upgraded with a weapon called the Clank Zapper which allowed him to damage enemies from his place on Ratchet's back. Shady Salesman Billy sold Ratchet the Levitator, a device which enabled Clank to fly using boost pads.
Clank often acted as Ratchet's choregos, acting as the voice of reason against Ratchet's brash personality. He was quite knowledgeable in a variety of subjects, which he never hesitated to show. Nonetheless, Clank has shown to be somewhat slower to realize certain things than Ratchet; for example, in Ratchet and Clank, he mistook the Captain Qwark robot for the real Captain Qwark, and only realized the truth when Ratchet told him so