You can use the AutoSave feature to load the game from the
previous turn if you're taking a nasty beating. Resurrecting dead units will bring them back with their
experience points intact, but if they have very few experience
points, your gold is better spent simply recruiting a new unit. Build the Guild and start sending out Thief units as soon as
possible it's the cheapest way to find out what sort of enemy
forces are inside cities and towers. Seriously consider using the Suicide function during battle if
you're positive you're going to lose and if you suspect that
enemy units will advance a level by fighting the battle to the
end.