Let's say in 5th ed D&D I take the Mobile feat, then use the Dash and Cunning Action. My PC's base speed is now +10, and I ignore difficult terrain, moving twice my new and improved base speed.
Using a halfling rogue as an example:
- Speed goes from 25 base, to 35 base
- Uses Dash as a bonus action, which gives a total of 70 that round
- Ignores difficult terrain.
- On top of that he can still make an attack against a creature (Mobile comes in handy here) provoking no opportunity attacks from that creature
- He continues to run past finishing his movement.
Can I call this Parkour/Freerunning as far as adding flavor and role-playing to the battlefield? It seems to fit.