We are just blocking a new 3 act play but I want to make it a 2 act play. Is there any rule on when a good stopping point might be. This play, Let's Murder Marsha, is continuous with no scene changes or time changes. There is one spot where no one is on stage for a minute and only knocking is heard. One of the actors is pushing for that to me the cut As the director, I think that is a boring spot and would rather have the cut when someone just discovered something surprising and let the suspense go on during intermission. What does anyone else think?

Our play this year will be close to two hours and that is just too long for most senior citizens to sit and that is who we are.

So you do not stop at any time in your last few plays?

In some cases you need to get permission to alter the play in any form including adding,moving,or eliminating intermissions. A lot of groups just do what suits them best.  Everywhere I work always has an intermission so they can sell refreshments.

Generally when I run into this situation, a three act play that doesn't really need two intermissions, I take the intermission between Acts 2 and 3.  Typically in the three act structure that's where the action should be at its crisis moment, so it sends the audience out to the restrooms excited to come back.  I would not take the break just because the stage happens to be empty for a moment.  In the case of this show where the action is continuous just run Acts 1 and 2 together as if the act break didn't exist.  My 2 cents.

A lot of times when I've been in three-acters, the director will have one standard length intermission (10 or so), and one that's just, say, 5 minutes for people to stretch and to preserve the dramatic tension point.  I honestly prefer that to any other solution.  But if you really only want one, then please use one of the act breaks the playwright has already created rather than making your own.