Not directly, but if the besieged throws all of his forces at the besieger and they ALL die, then the fortification is left undefended and (theoretically) should be breached in one turn and then captured without a fight.
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I'm in the IDF. (So any new reply by me is a very rare event.)
Ok, thanks. I thought that might be the case, but I've never seen it happen. What made me think that it might be possible was that I once took a province when an independent discovered a Harvester I had sneaking in the province. The Harvester ended up taking the province when the attacking forces routed.
One other question on siege breaking. If the defender attempts to break the siege and fails, will all of the defender's forces be destroyed (assuming all available forces are involved in the breakout) or will some forces survive and rout into a neighboring province or will they all retreat into the fortress?