Surprised

A creature is surprised if they don't notice a threat at the start of a combat encounter. A member of a group can be surprised even if the other members aren't. The GM determines who might be surprised by comparing the Dexterity (Stealth) checks of anyone hiding with the passive Wisdom (Perception) score of each creature on the opposing side.
While surprised a creature suffers the following effects:

• The creature can't move or take an action on their first turn of the combat.
• The creature can't take a reaction until the end of the first round of the combat (after each creature in the initiative order has completed their first turn).

You are no longer surprised at the beginning of the second round of combat.