We study the interaction between massive planets and a gas disc with a mass in the range expected for protoplanetary discs .
We use SPH simulations to study the orbital evolution of a massive planet as well as the dynamical response of the disc for planet masses between 1 and 6 \mathrm { M _ { J } } and the full range of initial relative orbital inclinations .

We find that gap formation can occur for planets in inclined orbits as well as for coplanar orbits as expected .
For given planet mass , a threshold relative orbital inclination exists under which a gap forms .
This threshold increases with planet mass .
Orbital migration manifest through a decreasing semi-major axis is seen in all cases .

At high relative inclinations , the inclination decay rate increases for increasing planet mass and decreasing initial relative inclination as is expected from estimates based on dynamical friction between planet and disc .
For an initial semi-major axis of 5 Â AU and relative inclination of i _ { 0 } = 80 ^ { \circ } , the times required for the inclination to decay by 10 ^ { \circ } is \sim 10 ^ { 6 } \mathrm { yr } and \sim 10 ^ { 5 } \mathrm { yr } for 1 \mathrm { M _ { J } } and 6 \mathrm { M _ { J } } respectively , these times scaling in the usual way for larger initial orbits .
For retrograde planets , the inclination always evolves towards coplanarity with the disc , with the rate of evolution being fastest for orbits with i _ { 0 } \to 180 ^ { \circ } . The indication is thus that , without taking account of subsequent operation of phenomena such as the Lidov-Kozai effect , planets with mass ~ { } 1 \mathrm { M _ { J } } initiated in circular orbits with semi-major axis \sim 5 Â AU and i _ { 0 } \sim 90 ^ { \circ } might only just become coplanar , as a result of frictional effects , within the disc lifetime .
In other cases highly inclined orbits will survive only if they are formed after the disc has mostly dispersed .

Planets on inclined orbits warp the disc by an extent that is negligible for 1 \mathrm { M _ { J } } but increases with increasing mass becoming quite significant for a planet of mass 6 \mathrm { M _ { J } } .
In that case , the disc can gain a total inclination of up to 15 ^ { \circ } together with a warped inner structure with an inclination of up to \sim 20 ^ { \circ } relative to the outer part .
We also find a solid body precession of both the total disc angular momentum vector and the planet orbital momentum vector about the total angular momentum vector , with the angular velocity of precession decreasing with increasing relative inclination as expected in that case .

Our results illustrate that the influence of an inclined massive planet on a protoplanetary disc can lead to significant changes of the disc structure and orientation which can in turn affect the orbital evolution of the planet significantly .
A three-dimensional treatment of the disc is then essential in order to capture all relevant dynamical processes in the composite system .