Pigtail 12/2 to 14/2 wire?

There is no prohibition to use larger wires.

But it is generally considered as poor practices when there is no specific reason for it, such as using a larger guage wire for a long run to reduce voltage drop.

Some one working on it in the future might be confused and think that the whole circuit is #12 and replace the breaker with a 20 amp one.

Also if you are making the splice in the can light box check the box fill. Those boxes are small.

Thanks, I'll also check the box for tight fit (good point). I'm hoping the 14/2 wire running to the main box will keep anyone from changing it to a 20amp. The 12/2 wire will only be used in the attic to connect the lights. Thanks again!

How can I connect these to two plugs? Two 14-2s and one 12-2. I don't know where they are leading to.