Radius is an area where task actually activates, it is a circle around pin location. Default radius is 10 meters, in most cases this should be alright. If you make the radius smaller, the task becomes harder to activate because of GPS inaccuracy, but it opens closer to the wanted location. Bigger radius is easier to activate, but it opens in a less controllable way.

A task that has radius of 5 meters or less are very hard to open in the real world. Location with radius of 0 meters does not open by GPS. Usually the radius should not be less than 10 meters.

It is possible to change radius, colour, default radius colour is grey (asphalt).

In general task you can edit the radius size only while creating a game on “Locations” or “Rules” tab. On location-specific task you can edit the radius while creating/editing specific task, on “Location” or “Rules” tab.