PCs and NPCs don't always use the same attribute values, so what works for one won't always work for the other. For example, for PCs, the attribute for Armor Class is ac , while for NPCs the attribute is npc_ac Under Game settings, scroll all the way near the bottom and you'll see where you can preset values for the token bars and bubbles. In the screen shot below, you can see where I've set the Bar 3 Link to npc_perception. You can set that to passive_wisdom instead. Be warned though: I found that because of the way some NPCs are set up in the compendium, passive_wisdom does not always equal the NPC's passive perception, and the npc_perception modifier is not always defined in the NPC's attributes. For that reason, always double-check the passive perception value reflects what's shown on the NPC character sheet. For instance, when setting up a token for an Abominable Yeti (From the D&D 5e Monster Manual), the passive_wisdom attribute is given as 11 while the passive perception is listed in the character sheet as 15.
