Horns is versatile, has solid spacing, and no 'natural' weak side. Here's an introduction from Lason Perkins.
I grew up in a "1-4 High" offense which I see as the horns precursor. Without a shot clock or three point shots, we still averaged 65 points a game by creating quality shots.
And coaching "limited" middle school players, underdogs won a playoff game with horns, scoring seven points in five possessions (above) with "down."
Horns offers on and off-ball screens, staggers, and advanced cutting. In the bottom left frame, Spain pick-and-roll is illustrated.
The challenge isn't finding ideas, it's developing players to execute with urgent cutting, crisp passing, and capable finishing.
It offers potential for early offense with:
1) high ball screen
2) filled corner with open 3 off help
3) weak side pindown (or backscreen 'hammer' action)
Horns versus zone. Screening works well, forcing remaining defenders to choose.
Horns "flexish" versus 2-3 zone.
Lagniappe (something extra). File away for a rainy day. Horns versus Box-and-1.
Lagniappe 2.
NBA horns sampler via Half court hoops and BBallBreakdown.