Let
f
:
G
→
R
n
f:G \to {R^n}
be quasiregular and
I
=
∫
F
(
x
,
∇
u
)
d
m
I = \int {F(x,\nabla \,u)\,dm}
a conformally invariant variational integral. Hölder-continuity, Harnack’s inequality and principle are proved for the extremals of
I
I
. Obstacle problems and their connection to subextremals are studied. If
u
u
is an extremal or a subextremal of
I
I
, then
u
∘
f
u \circ f
is again an extremal or a subextremal if an appropriate change in
F
F
is made.