The term for reggae’s offbeat guitar pattern is the skank.
A reggae skank is a short, staccato chord played between the main beats, often on the offbeats or on beats two and four. The guitarist quickly strikes and dampens the chord, creating a clipped, percussive sound rather than a sustained harmony. Keyboard players may double the figure, reinforcing reggae’s distinctive rhythmic pulse.
The technique developed from earlier Jamaican ska and rocksteady playing, which themselves drew on rhythm and blues and shuffle traditions. As Jamaican music slowed and evolved from ska through rocksteady into reggae, the offbeat stroke remained central but took on a heavier, more spacious feel.
The other options describe related reggae ideas rather than this guitar pattern. “One drop” refers primarily to a drum rhythm, “steppers” describes a bass-drum-driven reggae style, and “riddim” means a recurring instrumental rhythm or backing track. “Skank” can also refer to a dance, so the musical context matters.