  A leaper framework is a bar-and-joint framework whose joints are integer
points forming a rectangular grid and whose bars correspond to all moves of a
given leaper within that grid. We study the flexibility and rigidity of leaper
frameworks. Let $p$ and $q$ be positive integers such that the $(p, q)$-leaper
$L$ is free. J\'{o}zsef Solymosi and Ethan White conjectured in 2018 that the
leaper framework of $L$ on the square grid of side $2(p + q) - 1$, and so on
all larger grids, is rigid. We prove this conjecture. We also prove that
Solymosi and White's conjecture is, in a sense, sharp. Namely, the leaper
framework of $L$ on the rectangular grid of sides $2(p + q) - 2$ and $2(p + q)
- 1$, and so on all smaller grids (except for, trivially, the $1 \times 1$
grid), is flexible. In particular, we completely resolve the flexibility and
rigidity question for leaper frameworks on square grids. We establish a number
of related results as well.
