Strategies and tactics used and mentioned in Erfworld. Some of them are the same as in Real World, some are used just in Strategy Games. Parsons Plans has in-depth descriptions of the ones used by Parson.
Tactic for fighting Sea Dwagons. A small boat is used to distract the Dwagon away from a ship it has attacked and an another ship is used to croak it. WB2014 Duke Forecastle - Part 6
Defeat in detail
Large portion of one's own force is used to destroy small parts of enemy force in sequence, rather than engaging the bulk of the enemy force all at once. Example: Parson's Siege Raids.
Fleet of flying mounts with high move are regularly deployed and redeployed so that a high priority unit (a warlord or a caster) can ride from any city to the front line or back. Gobwin Knob was the first side to use this tactic in large scale as it demands large amount of appropriate units.LIAB Prologue 21
Line of battle
Ships of the fleet form a line end to end so that they can attack enemy with full broadsides without the fear of hitting friendly ships.
Low value units are used to shield high value unit from enemy attacks.
Turning Natural allies
Divide and conquer
Side or equivalent entity claims neutrality regards to wars that rage across the Erf, allowing it's units to work as mercenaries on a contract basis for any side that is willing to take them. Examples: Charlescomm and Magic Kingdom.
Also known as vertical growth. Saving money on military expenses and using it to upgrade cities. Cities are of high level and well defended. Leads to a slow expansion and a well-funded side consisting of small amount of strategically important cities. Example: Delkey WB2014 Digdoug - Episode 5
Also known as horizontal growth. Money is used on military which is used to sacking and razing enemy cities to produce more money. Cities are kept on a low level and magic is used to artificially boost their defense. Leads to a fast expansion and a poor side consisting of large amount of strategically unimportant cities. Examples: Haffaton and Homekey WB2014 Digdoug - Episode 5