Answering a question within your field of study has a DC of 10 (for really easy questions), 15 (for basic questions), or 20 to 30 (for really tough questions).
Invisible Thing | Spot DC to Notice | Spot DC to Locate/Pinpoint |
Active Creature | 20 | 40 |
Living Creature holding still | 30 | 50 |
Undead still/Object/Paralyzed | 40 | 60 |
Per 10 Feet Away | +1 | +1 |
Invisible Thing | Listen DC to Notice | Listen DC to Locate/Pinpoint |
In Combat or Speaking | 00 | 20 |
Moving Half Speed | MS Check result | MS Check result +20 |
Moving at full speed | MS Check result -5 | MS Check result +15 |
Run/Charge | MS Check result -20 | MS Check result |
Per 10 feet distance | +1 | +1 |
Behind door/Stonewall | +5 / +15 | +5 / +15 |