Playbooks

Not in any team playbook.
RPO Peek Slant out of Shotgun Doubles Y Off is a run pass option built off inside zone action to the backfield. The QB peeks the slant route from the inside slot receiver while the outside receiver on that side runs a hitch to hold the flat defender, and the offensive line executes the standard zone blocking scheme up front. This is a numbers based RPO: if the alley defender crashes down on the run fit, the QB pulls and fires the slant behind him, and if that defender sits or drops, the ball stays on the ground.
Watch the second level defender aligned over the slot slant, if he widens with the receiver at the snap the QB has a clean throwing lane. Man coverage shells with the nickel or linebacker locked in man on the slot receiver get gashed by the slant since the flat route occupies the underneath defender. Zone coverage that keeps a linebacker spying the box run fit will bait the QB into pulling the ball, so disciplined defenders should shuffle rather than fully commit downhill. User controlled lurk defenders sitting in the passing lane between the box and the slot can jump the slant read, forcing the QB to check down to the run. Aggressive run blitzes off the edge do not affect this concept much since the read is inside, so interior gap discipline matters more than outside contain here.
Pre-snap, identify whether the play side alley defender (usually a linebacker or slot corner) is sitting in the box or shaded outside to take away the slant window.
If you see a two high shell with soft corners and the flat defender staying wide, hand it off and trust the zone blocking to work behind it.
If the linebacker or nickel triggers hard downhill on run action, pull the ball immediately and throw hot to the slant before the window closes.
Use this on early downs (1st and 10, 2nd and medium) since the run/pass balance keeps defenses honest and discourages aggressive blitz calls.
Pair this with Inside Zone and RPO Zone Peek from the same set so the defense cannot key on the mesh point tempo, then mix in Slants or Y-sail once they start sitting on the RPO look.