Tell me an EXACT szenario situation, with the EXACT szenario notes,
then you can get indeed a more specific answer, what happens with this unit in exact this situation
(and i can refer to the exact passages in the rulebook and/or FAQ).
Thanks for the reply Bayernkini. The situation was this: Russian foot artillery unit with two blocks remaining are one hex from their side of the board. They receives three flags from French foot artillery. The Russian guns retreat one hex for the first flag and that's fine. The second flag, however, would take the Russian blocks of the board. Whats the correct way to resolve this and how do victory banners work in this instance? Thanks again.
What about this part of rulebook, page 13, left column (but read the complete Retreat section, for all possibilities)
• If the unit cannot retreat, because its retreat path is occupied or it is forced to retreat off the limits of the battlefield, one
block must be removed from the unit for each retreat hex of movement that cannot be completed.
So the short answer is a "forced" retreat from the base line causes a block removal for each hex the unit cannot perform a retreat move. If all the blocks are removed, the unit is destroyed and your opponent gets a victory point.