Surprise and the start of combat

Surprise (RAW) is a pretty murky area and requires a fair amount of GM discretion to be applied.

Surprise according to RAW

• The DM determines who might be surprised.
• If neither side tries to be stealthy, they automatically notice each other.
• Otherwise, the DM compares the Dexterity (Stealth) checks of anyone hiding with the passive Wisdom (Perception) score of each creature on the opposing side.
• Any character or monster that doesn't notice a threat is surprised at the start of the encounter.
• A member of a group can be surprised even if the other members aren't.

What I'm going to do about it

It would be unreasonable and unrealistic that PCs "always expect an ambush" but I also don't want being surprised to feel unfair when it happens. To that end, a few guidelines about how I plan to treat surprise:

1. When the party is not caught completely off guard, a certain amount of position adjustment (within reason) is both expected and allowed.
   • Saf's player has stated that she is likely to be positioned (when the party is in a group) close to some place to hide or take cover, where it is possible/reasonable to do so (usually within 10-20' of the "party" pawn).
   • If players have a "[Character] was doing [activity] so it makes sense that [character] would be [position, status, or situation]" justification, they can raise it when we're setting up the tokens for the combat or dissolving the "party" pawn.
   • I will commit to asking a few questions when combat is about to begin, but if the characters are taking precautions ("I have my weapon out and shield up" or "I am posted up behind this corner" or "I move back beyond what I think the blast radius might be") it's in everyone's best interest to both describe that and make the DM aware.
2. Surprise involves not being aware of a threat, and may be a result of being hidden or otherwise difficult to perceive. If a player feels their character might be affected by this, they should speak up when the combat is starting.
3. If a creature is hidden at the start of combat, and there are surprised creatures, the hidden creature will still be treated as hidden in reference to the creatures that are surprised until after their turn is over. This specific case is technically an exception to the guidelines about moving while hidden.
4. There's a bit of muddiness around starting initiative if the whole passel of enemies can't see the party - whole rounds could go by while all players are not yet perceived, so surprise would happen later than the first round of the combat. Being clear about when combat starts and when creatures are surprised is going to require significant communication.