In this paper we show that ambiguities and approximations common to conventional three‐body treatments of πD scattering can be largely eliminated. Thus, by employing a general dynamical framework which simultaneously describes the reactions NN→NN, NN↔NNπ, NN↔πD, NNπ↔πD, and πD→πD, uncertainties engendered by the relativistic reduction and off‐shell extrapolation can be suppressed by demanding that NN elastic data (which are most sensitive) be correctly reproduced. With this constraint predictions for πD scattering are sensitive chiefly to the deuteron wave function, defining a model‐independent nuclear probe.