  Using 2-dimensional (2D) magnetohydrodynamics (MHD) simulations, we show that
Petschek-type magnetic reconnection can be induced using a simple resistivity
gradient in the reconnection outflow direction, revealing the key ingredient of
steady fast reconnection in the collisional limit. We find that the diffusion
region self-adjusts its half-length to fit the given gradient scale of
resistivity. The induced reconnection x-line and flow stagnation point always
reside within the resistivity transition region closer to the higher
resistivity end. The opening of one exhaust by this resistivity gradient will
lead to the opening of the other exhaust located on the other side of the
x-line, within the region of uniform resistivity. Potential applications of
this setup to reconnection-based thrusters and solar spicules are discussed. In
a separate set of numerical experiments, we explore the maximum plausible
reconnection rate using a large and spatially localized resistivity right at
the x-line. Interestingly, the resulting current density at the x-line drops
significantly so that the normalized reconnection rate remains bounded by the
value $\simeq 0.2$, consistent with the theoretical prediction.
