Shadow Roll: Why are the enemy units able to detect my Ninja hiding many tiles away around a corner?

Question

Accepted Answer

The Shadow Roll represents the Ninja character's ability to hide from all the senses.  While they might be hiding in the shadows, they might be making a large amount of sound, have an unusual scent. or shake the ground when they move.  
 
The lord's units are using all of their senses to search for intruders, making it difficult for the Ninja to stay hidden while moving about the castle.

Frequently asked questions

Shadow Roll: Why are the enemy units able to detect my Ninja hiding many tiles away around a corner?