Quick post, Monster Johnston did this derpicore thing, and this was something else I did for it. Maybe he included it here already? Yes he did.
But I'mma post it again anyway. It took me like a whole ten minutes to think up, coz that was the whole entire of the game. Badger other people to make wack mechanics or material for your use with a limited time frame to do so. In exchange you agree to be a badger target for other people.
It's a great game, I recommend it.
First you need to know how fast you are going.
flying at brisk walk is 1d1
human running speed is a d4
horse trotting (cantering maybe?) is a d6
fly spell is a d8
broomsticks/flying carpets is a d10
rocketized versions of these is a d12
something faster than that d14
but wait even more absurdly fast is a d20
as above but with sweet paint job d30
(alternate version: assign die based on who is in the race right now, and not objectively. So If everyone has a horse then all the average horses get a d8, all the ponys get a d6 and all the mighty chargers get a d10. Or even more delineated if needed )
Each chase participant rolls their dice each round. Highest gets furtherest ahead.
You can choose to roll a dice any size smaller than you would normally.
YOu can also choose to roll a dice size one bigger than you would normally, but on the next round you have to roll one smaller.
Because every round the d.m is rolling an obstacle die. If your roll is higher than the d.ms
you have bounced off or directly collided into something. You take
damage = what the your die rolled and must make a dex check or come to a
complete stop. You also take additional damage = how much you failed
the dex check by. Modify this check by your (or mode of transports, which ever is bigger) size modifier (if any).
Needless extra complication bit:
If it you are around about the same size as you form of transport, you both take damage. IF you are a lot bigger than your mode of transport, then just you takes damage, unless you roll a 20 on the dex check, in which case you both take the damage. IF you roll exactly your dex, then just your mode of transport takes the damage.
If your mode of transport is atleast twice your size then split the damage 50/50, unless you roll a 20 on that dex check, in which case just you.
If you succeeded the dex check you are still in the race!
size of the obstacle die depends on how much crap is the way. A
typically sparse but with a few potential ghetto brakes room is a d20.
Examples of this would a large dining room, a big cave with a few stalagmites, a village street on a quiet night.
and on the other end of the scale is a crowded market place or a dense jungle which is a d4.
forests of endor would be a d12 . Wait which would make speeder bikes
have a bout a 50/50 chance of crashing into something each round. I
OKAY RULE FOR LONGER RACES EVERYONE GETS TO ROLL
TWICE AND CHOOSE WHAT RESULT THEY WANT TO USE AND THEY CAN CHOOSE AFTER
THE OBSTACLE DIE IS ROLLED UNLESS VIEWING CONDITIONS ARE BAD
OR something. Whatever you get the idea.