Renting and covering one of the bowling with people large balls where you are strapped inside a bowling ball and rolled towards the pins (Party rental type thing) might be a good idea for the rolling rock as long as nobody is inside as a safety thing. Having that steel frame for the large ball done already and even round would save time and money. Just a question of coming up with a say chicken wire and dutchmen covering for it and painting.
Be sure if that's a solution that you work closely with the rental company as they might not wish for their ball to have stuff attached to it or take the chance of paint dripping on it. Many things from the party rental companies including rock climbing walls and blow up obsitcal courses might be of use, if not those running the company might take your production under their wing as long as sufficient advertising is met. Brain storm with them where possible for how their stuff is made, what they have available and solutions to challenges.
Perhaps if possible the school's TD for the show could by way of getting that rental company manager involved become a co-TD for the show with that of the rental manager that might just be tickled pink with the concept of and involvement in your show.
Study also the pins for use in how to do other props or scenic elements that need to be crashed into or broken every night than ready for the next show.
Brain storm ideas and concepts first, than present specifically such as the ball above in what you need. Than request here and to all the production team a brain storming how to achieve this type of thing. First the idea and wish list - which you have time to pull off and in more than just effect will work within the realistic bounds of the story, than figure out how to make that effect a reality. Design the show first, than figure out hot to do it.
Remember the production triangle also. (Believe this is it.) Do you want it good, fast or cheap. Cover up one of these words in a triangle for the goal and this than as specifically stated will land the desired result with the others suffering to some extent. Cover up two parts of the triangle and the final one suffers a lot more. Having all three is much more difficult and should not in most things be expected.
After that, as with others, what effects would you wish to show?
ok, i'm a little more clear on the show now... it takes place inside a pyramid, and there is also a scene that takes place on top of two MOVING train cars. the way i'm going to do this is with lights and sound... not actually moving the set pieces. basically, i need ideas on how to, inexpensively, turn our stage into the interior of an ancient egyptian pyramid
could get compex but old movies used to use some form of rolled up back drop they could reel out when they had say a car that was stationary but wanted it to seem as if that car was moving by way of changing background.
IF you have a fly system, perhaps doing some form of ceiling panel covering the entire stage hung from it that is adjustable if not at times uniformly overly low and otherwise changing might be fun. This as with movable scenery panels to simulate walls which could move from place to place to simulate walls or hallways in a scene by scene type of thing, much less start moving in for a effect, or allow for spears to come in from between them etc. Given darkeness, shadows and large blocks making up the walls, it should be easy enough to get away without seemless walls or large gaps between scenery.
I would think some form of narrow passages and short ceilings would be fairly accurate - this given for the stage it might need to be more of angles leading to narrow upstage parts out of visibility from the audience requirements. Still if the upstage is narrow and grows very sort and even narrow, one might get the idea even if the down stage area is wider. See single point perspective designs of Renaissance scene design for opera.
Could even make a ceiling that gets to be really short the further you go up stage and not move it at all in not having a fly system or not really wanting to move it. Some over bearing and seemingly weighty ceiling panel might add to the danger effect, much less size and deep inside the pyramid type of atmosphere.
Wouldn't even need to match moving walls to the angle of the ceiling persay as long as the ceiling and floor made one large plane of blocks. Little dark spots by way of walls not matching the angle or exact height than could be a stage convention in not matching up. Gaps between walls, not matching the angle, as long as they are panels and painted as if blocks, and what's in the background is black, the audience will connect the panels together as long as the acting is sufficient that they don't otherwise have time to look at the scenery because they are board with the show. This in portable castered wall panels would also be a slightly less realistic design choice that's perfectly acceptable.
Rake the stage also for some fun in running up and down stage and even if really bold match that of the intrusive ceiling. Your actors will curse you than get to love running up and down stage with the action. There is certain maximums you will need to work with in a rake but the steeper the better if doing a lot of running about and fast action. Much les a short depth to the stage.
Given scene changes I would force some similarity of location by way of a ceiling that is opressive in angle most overall.
Anyway, it's a unifying scenery element to the location as an idea where than you could do the walls to change location within the area.
Study into ceiling panels will show how to do them and allow for top lighting.
That's my inital design thought or picture were I designing the show by way of concept given. Granted I would read the script a lot and be very prepaired to throw out the initial design concept, but would otherwise if it seems to fit for a concept even if intial, look into it some.
Given a flatstage, it's easier to move and have stay there wall panels much less their height is slightly easier to make somewhat constant at least in reference to a sloped ceiling.
A Polygon (is this correct for a rectangle with three different lenghts but pararallel on one side?) Anyway, that's the ceiling I would go with. I would even light the ceiling slightly to add to the massive weight above one effect. This by way of making the walls shorter than going all the way to the ceiling.
Forced perspective would make it difficult in randomly arranging wall panels given blocks would have to get shorter the further upstage they got. Still if you did movable walls but lit ceiling you could have big rooms or small rooms but all under an opressive weight above you.
Beyond advantages and fun of a raked stage otherwise - where you would probably have to track the wall panels parallel to the procenium - that could be done and done very well, the raked stage would also allow for some movement in the stagedeck and a lot more seeing of it. Who's to say that you can't have quick releases in the stagedeck to have a rake turn in parts flat or even reverse sloped. Much less the raked stage would allow for upstage ground row effects and even trap doors. Stuff coming in from above below and the sides.