it (all) depends
The possibility or likelihood of some outcome depends on one or more unspecified factors. A: "So, would you be willing to join our company?" B: "Well, it depends—what kind of salary are we talking about?" Is it legal? Yes. Is it ethical? Well, it all depends.
that (all) depends
The possibility or likelihood of some outcome depends on one or more unspecified factors. A: "So, would you be willing to join our company?" B: "Well, that depends—what kind of salary are we talking about?" Is it legal? Yes. Is it ethical? Well, that all depends.