For my pattern, I've bought a set of four size seven DPNs but I know that some patterns say three are necessary, others four. Does it matter how many I use? My pattern doesn't specify so I'm not sure if I should use three DPNs or four.

It's a beret, if that makes any difference.

Thank you!

You need at least 4. Three will have stitches on them, and the 4th will be used to knit off of those.

Oh! Well, duh, haha. Thank you so much!