In order for Zombies, Run! to track you if you’re indoors or can’t use GPS you’ll need to use either the Accelerometer tracking or Constant Speed option. Accelerometer tracking may also be called 'Step Counter' or 'Step Tracking' mode.
When using Accelerometer tracking Zombies, Run! will track your steps and initiate Zombie Chases as normal by using your phone's accelerometer. While using Accelerometer tracking, however, the app cannot show you a map of your run on ZombieLink.
To use Accelerometer tracking you need to tap on the tracking button in the mission options bar and select Accelerometer/Step counter. Once you’ve selected this you’ll see an option to input Stride length appear. Tap on this and a picker will appear where you can input your stride length in either metres or feet. Once you've done this tap the ‘back’ button to return to the missions menu where you can start your accelerometer tracked run.
If you're not sure how to calculate your stride length then please see our FAQ page about this: How Do I Calculate My Stride Length?