two-hander 
noun
A play for two actors.Essentially a two-hander, he allows actors no physical contact and revokes his licence to shock....
- ‘I've only ever done two-handers at drama school [the Webber Douglas School in London] but this is even more intense because I don't leave the stage, apart from the interval,’ he says, in his trademark deadpan, chilled London accent.
- A half-hour two-hander, Laundry at 4am is a small theatrical gem.