How would you change the CR / XP if you gave your monster 2 separate attacks?

[SeDe]

So in order to design my encounters more interesting I read about the "action economy"

https://gamingeveryman.wordpress.com/2014/02/24/55/

and I like the results so far.

Now I'm asking myself the question if it would be feasible to give one monster 2 (3, 4 ... X) seperate Attack Actions with different Initiative rolls. How would that Change my CR / XP?

Let's take a young white dragon. It's CR 6 @ 2,400XP. If I take 2 Dragons that would equal 4800 XP and according to the "action economy" approach it would be a CR of 8.

If I just take one Dragon but give him 2 Attacks, essentially making him 2 Dragons in one body, how much XP would that amount to? (And CR)?

Your take?

[Matthew Downie]

A regular white dragon can already attack 5 times in a round. Are you increasing this to 10?

[SheepishEidolon]

Well, two separate dragons would be CR +2. A single dragon with doubled damage output still suffers from having the usual action limitations and its normal hitpoints - so I'd say CR +1. If you feel 3,200 XP (only 4/3 of 2,400) is not enough, feel free to hand out 3,600 (3/2 of 2,400).

[CampinCarl9127]

There isn't a hard rules answer for this. It's like the opposite of gestalt; increasing their action economy without increasing their resources.

Flagged to be moved either to advice or houserules. You will probably find more help in one of those places.