にかかっている

にかかっている means "depends on", "rests on": an outcome hangs on one decisive factor. The outcome is the topic with は, and the factor takes に.

It is the ている form of かかる, "to hang on", and you meet it in that form almost every time.

With かどうか and question words

The outcome is often an open question: a clause ending in かどうか, "whether or not", or one built on a question word.

にかかっている or によって違う

English "depends on" covers two ideas. にかかっている says one factor decides how things turn out. When the answer simply varies from case to case, say によってちがう違う. しだい次第だ is the close relative of にかかっている: one factor decides the outcome.

• × 値段は店にかかっている → 値段は店によって違う

にかかっている also says something important is at stake, so it sounds heavy for small everyday choices.