Rogue subclass
Scout
Wilderness expertise, reactive movement, and ranged skirmishing.
Scout starts by changing the normal Rogue play pattern through Skirmisher; Survivalist, giving the subclass its first clear mechanical identity.
Later features such as Superior Mobility, Ambush Master, Sudden Strike expand that identity at higher levels, so the subclass has a clearer role in combat, exploration, utility, or support.
Skirmisher; Survivalist
3rd level
Move as a reaction 
D&D Portal - Reaction Action rule Reaction is an action economy rule used to
describe what a creature can do on its turn. Full link: https://dnd-portal.com/rules/actions/reaction/ when enemies approach without provoking from that enemy, and gain Nature 
D&D Portal - Nature Skill reference Nature is a skill used for ability checks
in relevant situations. Full link: https://dnd-portal.com/rules/skills/nature/ and Survival 
D&D Portal - Survival Skill reference Survival is a skill used for ability checks
in relevant situations. Full link: https://dnd-portal.com/rules/skills/survival/ with doubled proficiency.
Superior Mobility
9th level
Increase walking 
D&D Portal - Walking Movement rule Walking is a movement rule used during
exploration, encounters, and combat. Full link: https://dnd-portal.com/rules/movement/walking/ speed D&D Portal - Speed Movement rule Speed is a movement rule used during
exploration, encounters, and combat. Full link: https://dnd-portal.com/rules/movement/speed/ and climbing 
D&D Portal - Climbing Movement rule Climbing is a movement rule used during
exploration, encounters, and combat. Full link: https://dnd-portal.com/rules/movement/climbing/ or swimming 
D&D Portal - Swimming Movement rule Swimming is a movement rule used during
exploration, encounters, and combat. Full link: https://dnd-portal.com/rules/movement/swimming/ speeds.
Ambush Master
13th level
Gain initiative 
D&D Portal - Initiative Roll Combat rule Initiative Roll is a combat rule used by attacks,
damage, defenses, or turn order. Full link: https://dnd-portal.com/rules/combat/initiative-roll/ advantage; the first creature you hit becomes easier for everyone to attack for the round.
Sudden Strike
17th level
Make an extra bonus-action attack and potentially apply Sneak Attack to a second target.
FAQ
What is the Scout Roguish Archetype?
The Scout is a wilderness and mobility Rogue that can retreat when enemies close in, gains enhanced Nature and Survival expertise, and becomes especially dangerous during the first round of combat. At Rogue 3, Scout adds reactive movement and wilderness expertise while the character continues to gain the Rogue's normal Sneak Attack, Cunning Action, Uncanny Dodge, Evasion, and Reliable Talent.
Read more: Scout 
D&D Portal - What is the Scout Roguish Archetype? Scout FAQ The Scout is a wilderness and mobility Rogue that can retreat when enemies close in, gains enhanced Nature and Survival expertise, and becomes especially dangerous during the first round of combat. At Rogue 3, Scout adds reactive movement and wilderness expertise while the character continues to gain the Rogue's normal Sneak Attack, Cunning Action, Uncanny Dodge, Evasion, and Reliable Talent. Full link: https://dnd-portal.com/faq/scout/what-is-the-scout-roguish-archetype/
What are the main Scout features?
Scout is a highly mobile wilderness Rogue. Skirmisher lets the Rogue retreat when enemies close in, Survivalist makes Nature and Survival exceptionally reliable, Superior Mobility increases speed, Ambush Master improves the party's opening round, and Sudden Strike creates an unusual high-level opportunity to pressure two targets.
Read more: Scout D&D Portal - What are the main Scout features? Scout FAQ Scout is a highly mobile wilderness Rogue. Skirmisher lets the Rogue retreat when enemies close in, Survivalist makes Nature and Survival exceptionally reliable, Superior Mobility increases speed, Ambush Master improves the party's opening round, and Sudden Strike creates an unusual high-level opportunity to pressure two targets. Full link: https://dnd-portal.com/faq/scout/what-are-the-main-scout-features/
How do you build and play a Scout Rogue?
Build the Scout on top of a normal Dexterity-focused Rogue, then invest in the secondary abilities and skills that support the archetype. Stay difficult to pin down. Use Skirmisher to preserve distance when enemies approach, then use Cunning Action and the Rogue's normal movement on your own turn to choose a better firing or flanking position. At high levels, exploit Ambush Master by hitting a priority enemy early.
Read more: Scout D&D Portal - How do you build and play a Scout Rogue? Scout FAQ Build the Scout on top of a normal Dexterity-focused Rogue, then invest in the secondary abilities and skills that support the archetype. Stay difficult to pin down. Use Skirmisher to preserve distance when enemies approach, then use Cunning Action and the Rogue's normal movement on your own turn to choose a better firing or flanking position. At high levels, exploit Ambush Master by hitting a priority enemy early. Full link: https://dnd-portal.com/faq/scout/how-do-you-build-and-play-a-scout-rogue/
How does Scout interact with Sneak Attack?
Scout uses ordinary Sneak Attack for most of its career. At 17th level, Sudden Strike creates a rare opportunity to apply Sneak Attack twice during the same turn, but only if the second Sneak Attack is against a different target. The usual weapon and qualification rules still apply to each attack.
Read more: Scout D&D Portal - How does Scout interact with Sneak Attack? Scout FAQ Scout uses ordinary Sneak Attack for most of its career. At 17th level, Sudden Strike creates a rare opportunity to apply Sneak Attack twice during the same turn, but only if the second Sneak Attack is against a different target. The usual weapon and qualification rules still apply to each attack. Full link: https://dnd-portal.com/faq/scout/how-does-scout-interact-with-sneak-attack/
How does Skirmisher work?
Skirmisher lets a Scout use its reaction when an enemy ends its turn within 5 feet to move up to half the Scout's speed. That movement does not provoke opportunity attacks. It occurs on the enemy's turn, so it can reposition the Scout before the Scout's next turn, but it consumes the reaction.
Read more: Scout D&D Portal - How does Skirmisher work? Scout FAQ Skirmisher lets a Scout use its reaction when an enemy ends its turn within 5 feet to move up to half the Scout's speed. That movement does not provoke opportunity attacks. It occurs on the enemy's turn, so it can reposition the Scout before the Scout's next turn, but it consumes the reaction. Full link: https://dnd-portal.com/faq/scout/how-does-skirmisher-work/