  In this article we study the Arnold conjecture in settings where objects
under consideration are no longer smooth but only continuous. The example of a
Hamiltonian homeomorphism, on any closed symplectic manifold of dimension
greater than 2, having only one fixed point shows that the conjecture does not
admit a direct generalization to continuous settings. However, it appears that
the following Arnold-type principle continues to hold in continuous settings:
Suppose that X is a non-smooth object for which one can define spectral
invariants. If the number of spectral invariants associated to X is smaller
than the number predicted by the (homological) Arnold conjecture, then the set
of fixed/intersection points of X is homologically non-trivial, hence it is
infinite.
  We recently proved that the above principle holds for Hamiltonian
homeomorphisms of closed and aspherical symplectic manifolds. In this article,
we verify this principle in two new settings: $C^0$ Lagrangians in cotangent
bundles and Hausdorff limits of Legendrians in 1-jet bundles which are isotopic
to the zero section.
  An unexpected consequence of the result on Legendrians is that the classical
Arnold conjecture does hold for Hausdorff limits of Legendrians in 1-jet
bundles.
  Dedicated to Claude Viterbo on the occasion of his 60th birthday.
