“Can you explain to me what a power budget is in kit design?”

It is easiest to visualize as a pie chart, because whenever you grow one slice of the pie, it forces the others to shrink.

So imagine you are designing or balancing a champion and you give her a big buff to her shields. This does a couple of things. In the pie-chart mentality, you are deciding that shields are more important than other aspects of her kit, such as maybe her movement or her burst damage potential. If by buffing her shields, you are making all of the pie slices closer to the same size as each other, then you may be making her a little more generic in terms of strengths and weaknesses, rather than having the sharper strengths and weaknesses that we believe makes better champions.

On the other hand, if you aren’t thinking about it in terms of a pie chart, then you may just be giving her more raw power across the board. Maybe she needs that and maybe she doesn’t, so you should be really deliberate about those decisions. If you aren’t trying to affect her win rate, but still want to emphasize her shields, then you may need to carve off power from somewhere else.

If the pie chart metaphor doesn’t work, then another way to think about it is as if you are building a character at the start of an RPG. You have 100 points to spend. You can put 20 points into all 5 attributes and end up with someone who is kind of bland. Or you can but 40 points into strength and 10 points into dexterity to create a clumsy bruiser type (with sharper strengths and weaknesses). What you can’t do is put 40 points into everything, because then you’re not staying within the [power] budget that the game is enforcing.

In terms of League, there isn’t an actual budget that we use. For example, we don’t charge a character a cost of 50 in order for her to get a move block on her Q. It’s an interesting thought experiment about whether that would work or not, but my suspicion is you would spend way too much time trying to accurately price all the myriad of champ abilities in order to plug them into the formula.

Instead we use power budget as a shorthand when talking to other developers on the team or to players. The conversation might be something like “I understand her mid-game wave clear is on the weak side, but I don’t really have the power budget to buff it without taking away some of her early game strengths.”

7/5/2017