Picking a Photo

As mentioned on Facebook, my library is having an amateur photo contest and I’d like to submit something, but I’m having trouble picking out a picture. Based on feedback from others and a few of my favorites, I’ve narrowed it down to 8 photos to choose from. I can only pick one, and I think I’ll submit either to Still Life, Animal, or Scenic categories.

Now the hard part, which one of these is the best?

Khan Academy Experiment–Absolute Values

I remember learning about absolute value equations in school. The only thing I retained was that they made V-shaped graphs and that was kind of cool, but I’m not sure I ever grasped an understanding of real-life situations where absolute values came into play.

So here’s an example (special thanks to Matthew DeLucas for suggesting the use case).  It’s extremely simple, but that’s okay because it’s supposed to be for Intro to Algebra stuff (it has some inequalities in there for good measure).  Note, it does not take into account the fact that the stage has bounds, so it’s still an oversimplified case.

You are making a 2D Fighting game (a la Street Fighter).  The part of the screen that is visible is 540 units wide, even though the stage is actually much wider, so you never want your players to be farther away from each other than the width of the visible screen (when players move the screen does not pan up and down, only left and right, so we only care about their positions on the x axis).  When the players get further away from each other than 540 units, the game should push them closer together.

If one player 1’s x position is 100, at what player 2 positions will the game need to push the players towards each other?

|x – 100| = 540

x = –440 or x = 640



Under what conditions will the game know that it needs to push the players together?

|Player1.x – Player2.x| > 540

|x-y| > 540


Thoughts on Okami

People who know me well know that Okami is my favorite game of all time. Recently, when playing through the HD release, I found myself at a particular moment in the game just before I had to stop playing to go get dinner with Nick. I was turning in a side quest, and was mentally time managing what I was going to do next – “I think before doing the next story quest I’m going to train up at the dojo on my way back to Shinshu Field and get the clover that I couldn’t get before, but I need to go to a shop and get more seed because I missed some birds back there. I wonder if I should farm up demon fangs and get that mirror teleport now or wait until after I do the next dungeon…”

It struck me how excited I was about doing ALL THE THINGS in that game. This is unusual for me, because in most games of this nature I tend to be a primary-path sort of girl. Even in Zelda games, which I enjoy very much, I’m never too concerned about finding all the heart containers or whatever. So I got to thinking, what is it about Okami specifically that makes me so excited about doing all the collections and side quests and essentially 100%ing the game?

Theory 1:

In many games, the story artificially drives my sense of urgency. I’m talking about when the story is like “oh no we must rush to the castle before it is too late!” My logic brain knows that I could go out and farm for experience, complete the secret side quest in the first area, AND finish the entire chocobo minigame series or whatever before going to the castle (and when I got there I’d still arrive just in the nick of time).

However, emotional brain doesn’t quite understand this. Emotional brain feels I need to book it to the castle as fast as I can, because something very serious is at stake. I think my tendency is to let myself get engaged in the experience to the point where emotional brain is sort of guiding things, so I readily go from story point to story point.

In Okami, the story has a lot of exciting moments, but when you get to a new place it tends to frame things as not being in too much of a rush. Your companion, Issun, will be like “you’re gonna love exploring the city, there’s so much to do! I guess we should investigate the weird thing about the queen at some point…but the city is so happenin!”

It is an ever so slight encouragement to do whatever the hell you please, framing the next story point as “yeah, we’ll get around to it.” Possibly this setup sets emotional brain at ease, and makes me much more enthusiastic about feeding all the bunnies along the coastline before actually going into the city.

Theory 2:

It’s possible that the only thing compelling me to do so much of the extra stuff in Okami is that I’m so starved for a game experience that speaks to me. I know in the back of my mind that it’ll probably be over 10 years before someone else makes a game of this scope with this amount of whimsy and personal Lisa Brown appeal, so I become desperate to squeeze every last drop out of the experience before leaving it.

What about you, internet? What games compel you to do all their extra things when comparable games do not?

Khan Academy Experiment–Intro to Algebra

So awhile ago on Facebook, I mentioned wanting to do a thing where I came up with a practical game development example for Khan Academy playlists.  This post is the first one!

I started with the Intro to Algebra playlist, and actually had kind of a tricky time coming up with an example.  I just wanted to do something simple with comparing two linear equations, but lots of things in games don’t end up being linear (the first idea that popped into my head was comparing acceleration and top speed between Bowser and Yoshi and seeing when Yoshi would overtake Bowser, but those aren’t linear rates).

After cycling through some more too-complex ideas, I settled on Gold Drip in MOBA games.  It’s a start, but even still it’s oversimplified for a few reasons

  • It doesn’t take into account other means of gold income or spending, only passive gold drip. 
  • It doesn’t address that you can’t actually buy the Philosopher’s Stone at the beginning of the game – that you can’t have negative gold
  • The per-10-seconds language would have tripped me up as a beginning algebra student, I think.

Anyway, it’s a start.  Please let me know if I blew the math anywhere.

The Scenario

In League of Legends, players earn money at a rate of 16 gold every 10 seconds and every player starts out with 475 gold.  A player can buy an item (Philosopher’s stone) for 700 gold that increases her income by 5 gold per 10 seconds.

So, normal rate (where s is seconds)

Total Gold = (16/10)s + 475

Philosopher’s Stone rate

((16+5)/10)s + 475 – 700

If a player buys the Philosopher’s Stone, at what time does she break even, after which her gold will overtake an opponent who did not buy the Philosopher’s Stone?  This is assuming neither player buys anything else or gains gold in another way.

(16/10)s +475 = ((16+5)/10)s + 475 – 700

(16/10)s +700= ((16+5)/10)s

(16/10)s+700 = (21/10)s

700 = (5/10)s


1400 = s (so 23 minutes and 20 seconds)


However, this would assume that you could buy the item from the very start and have negative gold.  How long would it take before a player could afford to buy a Philosopher’s stone?

s = (700 – 475) * 10 / 16

Let’s assume that you the designer want the Philosopher’s Stone to be OP  and pay itself off 5 minutes earlier than it does right now (s=1100 instead of s=1400).  How could you change the item’s cost to achieve this?  How could you change its gold gain rate to achieve this?

Changing initial item cost

(16/10)(1100) +475 = ((16+5)/10)(1100) + 475 – c

(16/10)(1100) =  ((21)/10)(1100) – c

1760 = 2310 – c

c = 550

Changing item’s gold gain rate

(16/10)(1100) +475 = ((16/10)+r)(1100) + 475 – 700

1760= 1760+1100r – 700

700 = 1100r

7/11 = r (this is 7 gold per 11 seconds)