Sense Ki

This ability allows the player to sense any living thing , regardless of terrain, within fifty feet + level of their location. Any rolls that involve a situation in which the player may not be able to use sense ki are at a disadvantage 1. Spells cast by a living thing are imprinted with ki and can be sensed. Sensing the ki of a living thing allows the player to make a reasonable estimate of their strength as well as race.

1Examples: picking locks, dodging projectiles, avoiding traps. 
2The definition of what is a "living thing" is at the DM's discretion.