The ability to produce force is fundamental to life at every scale. A great deal is understood about the individual molecules involved in force production, but far less is known about how they coordinate to produce whole-cell-level effects. In this talk, I present a simple experimental setup for producing cells with tunable geometric properties, and explore a mathematical model for how variations in cell geometry lead to changes in cell mechanical behavior, including the magnitude of force produced and the stability---or lack of stability---of cell symmetry.