If I understand correctly, given a complex vector bundle $\pi:E \to X$, its Euler class $e(E)$ is given by $$e(E)=c_k(E)$$ for $k \in \text{min}\{\text{Rank}(E), \text{dim}(X)\}.$
Do we have similar results for other bundles? Say:
1) Real vector bundle?
2) Projective bundle (a fiber bundle whose fibers are projective spaces):
i) Real projective bundle?
ii) Complex projective bundle?
iii) Quaternion projective bundle?
(needed to be oriented.)