Eyes of the Eagle and Initiative

Question

Eyes of the Eagle gives a bonus to Perception checks "that involve sight". Usually, a Perception check can be used for Initiative.
When does Initiative not involve sight?

Answer 1

When it involves the other senses.

For most characters, these are Vague Senses, but can be improved to be Imprecise or Precise.

Do you hear the bandit step on a branch, or smell them because they haven't bathed? You're still rolling perception for initiative (unless the circumstance allows you to roll something else, as normal).

There are also Special Senses such as Tremorsense.

When one creature might detect another, the GM almost always uses the most precise sense available. (Vague Senses)

If the opponent cannot be seen, then it falls back onto these other senses. These rolls would not gain the benefit of the Eyes of the Eagle.

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