This is gonna be a lot of math and maybe some rambling, but I do believe that it pertains to the topic of character creation. This is more of, what would GMs do if presented with this situation and would they allow a player to do this kind of thing. Personally, I am going to preface that I enjoy an 11 or 12 Agility Character, but we'll get into the details farther down. Enjoy the math and any comments are welcomed!
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So, I think there may be a problem with Agility and movement speed rates. Perhaps this is going into munchkining a bit. So, the maximum Agility you can get with just Bioware at Character Creation is 11, or you can get up to 12 as an Adept. This means that an Elf (since that's the metatype you need), can move 22/44 Meters per 3 seconds with Bioware, or 24/48 Meters per 3 seconds as an Adept.
That means that for someone with Bioware, you're going 7.33 meters per second while walking, which means you can walk a mile in 3.65~ minutes. I understand that this is Shadowrun, not real life, so augmentations mean a lot, but the world record for a human is 3 minutes, 43.13 seconds at a full out sprint. So, walking, this guy beats the current world record. This bioware guy can jog 14.67 meters per second, which means he covers that mile in 1.82 minutes. That's moving at about 32.7 miles per hour at a jogging rate. You can go even faster with Sprinting. This is already ridiculous compared to reality. Even if we were to triple our reaction times (such as Synaptic Boosters 3 or Wired Reflexes 3 approximately), I still am not sure if I could dodge a car moving that fast at me, and this is a metahuman that isn't large and obvious.
Now, as an Adept, you can get an Agility of 12. You are walking 8 meters per second, which means you cover a mile in 3.35~ minutes. Your jogging rate is 16 meters per second, so that means you cover the mile in 1.67 minutes. This character is now moving 35.79 miles per hour. Again, add in Sprinting and it gets pretty ridiculous. Think of how fast you see a car move and you notice it's going 20 miles an hour. 35.79 miles an hour is faster than probably a good 80% of speed limits you'll find outside of a highway.
I mean, think about the average metahuman. They are supposed to have an Agility of 3, and I've seen plenty of characters with an Agility of 2. Their absolute maximum rate doesn't even come close to this characters walking rate. That's right, a normal metahuman at a full out sprint, going as fast as they can, doesn't move as fast as this guy when he's walking. My house is maybe 60 feet wide. That means in the space of 2 seconds, not even a combat turn, this character can walk from one side of my house to another. He can outdistance all Pistols, even a heavy Pistol, in one Combat turn using his Walking rate. He can outdistance SMGs with his running rate, and put Assault Rifles into the Long distance category. Or, if I wanted to, I could move towards a guy and take him down. If this character goes first, he can literally walk up to the guy who is training a pistol on him at max range and take him down before anyone can even react to try and raise a gun. I mean, if you saw this guy move, he's probably a blur at that point. Shake your fingers really fast in front of your face, and notice how you can't see them all that well and you can't tell where they are going to be. This guy moves probably 10x faster than that.
The fastest dracoform in the SR5 book, the Feathered Serpent, has an Agility of 9. Not only do you have a higher Agility, but you have a higher movement rate even though they have larger multipliers! Their "running" movement rate is Agility x 5, which equals 45 meters per combat turn. An Agility 12 character has a "running" movement rate of Agility x 4, which equals 48 meters per combat turn. You know how you never turn your back on a dragon? Well, it's still probably a good idea, as they can outfly you, but you are still moving faster than the fastest dragons in the book. Everything else is even slower.
All right, you might think I've sort of made my point. However, there's more. Let's have my friend the Magician with the ability to conjure spirits help me out. I have the same 12 Agility. Let's say he summons a Force 14 Spirit and have them use Movement on me. They can multiply my movement speed by 14. That 12 Agility? That turns into 168 Agility! That's a "walking" (use the term loosely since it doesn't really apply) rate of 336 meters per combat turn = 112 meters per second. You can "walk" a mile in .239 minutes, or 14.34 seconds, which is about 3.33 combat turns. So, you are walking at a rate of 250.536 miles per hour. You are moving at 1/3 the speed of sound. How about "running"? Well, you are running at 672 meters per combat turn = 224 meters per second. Say goodbye to that mile by "running" it in .119 minutes, or 7.18 seconds ~ 2 Combat turns. Keep on "running" at 501.06 miles per hour. Roughly 3/4 the speed of sound. Thought you could dodge an Agility 12 Character coming at you before? Think again. Now, hitting something while doing this may actually flatten a character, but let's imagine something here for a second. This character picks up a brick, holds it arm's length out, does a "running" action at an enemy. Right before he hits the enemy, he drops the brick, which is still moving forward at 501 miles per hour due to inertia. I think we can imagine the amount of damage that enemy would take, but I would ballpark it around 500P damage. Not to mention this guy can outrun a sniper rifle's range within 1 Combat turn, can probably go around a large building a couple of times in 1 turn, or can simply walk through all of the security before it, or the guards in charge of it had time to notice him. Oh, and you know Astral movement that is supposed to be ridiculously fast? Well, the "running" movement of Astral still beats you since it clocks in at 5 kilometers per combat turn (1.67 kilometers per second), but you pass the "walking" rate of 100 meters per combat turn (33.33 meters per second)!
You might say, "Well, a Force 14 Spirit is really hard to summon and is not something that should be used often!" While it's true, a Force 10 one can really easily be summoned, unless the GM decides to edge the roll. All right, you want something most GM's won't edge? Force 7, since you aren't oversummoning. You multiplier is only 7, instead of 14, but you're still rocking an Agility of 84 for movement. "Walking" is still at a rate of 168 meters per 3 seconds or 56 meters a second, and "running" is at 336 meters per 3 seconds, or 112 meters a second. You are still "running" at 250.526 miles per hour, walking at half that for a not so small 125.263 miles per hour. I'd like to see a dragon outrun that, or even that one Adept who has Combat Sense 7 with max dice pools for 30 dice to dodge a melee attack coming at them at 250.526 miles per hour. Good luck having your Improved Reflexes 3 allow you to register that.
Let's not discount that in both cases you still have a high Force spirit on your side. Let's also not discount, that all of this is easily available at Character Creation. This is no ridiculous initiation shenanigans, it doesn't involve super secret bioware, it's not a ton of karma invested. It's literally just pushing to the max your Agility in regards to movement at Character Creation. Oh, and did I forget to mention that even without a spirit, you're still gonna have a super high Sneaking skill, default to 11 dice on Agility skills, and probably be rolling 20 or more dice to use a ranged weapon.
So, my question really is this. How would someone handle something like this in a game? Would you allow it? Would you allow the 12 Agility but not the super massive Spirit boost to movement speed? I personally would allow the 12 Agility due to how fun it is, but honestly, do the numbers break a bit at this point? Sure, the same can happen with a Decker and his Logic, but when a single guy can most likely annihilate any type of security available to a starting run's budget (I mean the GM's controlled security), you kind of have a problem. Although, I have to say. If your role is combat, then you're probably set with this kind of build, but I can see some GM's laying down the law when it comes to this; since it can almost be considered abusing the rules.
Side note: Who needs a vehicle for transportation when you can probably outrun most of the bikes? Although, I guess people would find it a little strange if someone flying by at 30+ miles per hour was just running around ...