Improvisation

I was invited to a match in the improvisation. We were planning a sleepover at Ann's home and we found out the match is in the same evening, so we first went there.
We (Ann, Kriza, me and Lan) decided to meet in the metro station Kobylisy. Fortunately we met with a long enough time reserve, cause Lan somehow confused the time and arrived half an hour later, after Kriza's SMS. We also met Kadak. She was acting as a side referee, so she couldn't be waiting with us, but at least she told us how to get there. We arrived to the DDM Premyslenska just in time.
The room was rather small, but there were also only about forty people, mostly friends and relatives of the actors. I knew a half of them (Ondra, a42, Fela, Masha). Also there was Kadak as a side referee.
How does it work? There was a lot of variation (after all it's impro), but all in all there are two teams, comprised each of 4 players. There is a main referee assisted by two assistants. In the beginning, the spectators write themes, then the main referee draws them randomly. The teams have to improvise on the selected topics, usually during two minutes. The teams cooperate.
In the end of each performance, spectators vote, which team was better. However the score is not really a concern, rather the fun of both actors and spectators is.
I was quite impressed by this and maybe I'll a visit to the impro training to see if it'd interest me.