theatres-- are stalls always flat or tiered?

[bishboschone]

please

IME they are usually flat (or maybe with a very slight slope).

HTH

Yeah.that's what I thought, do you think the next row back would be better? So tricky to tell which seats are the best .thanks for replying

If it is a London venue then look at Theatre Monkey which will give you details of best seats for each price range etc.