There are 4 important
BRB concepts you have to understand for the effective use of chaff.
• Units cannot move within an inch of another unit unless charging.
• A unit must conform to a unit it charges.
• A unit must declare a flee reaction to a charge when already fleeing.
• A unit may only redirect a charge once.
There is also one other tactical concept, it is better to engage in combat on your turn then your opponents. This is simply due to the opportunity to influence that combat through Hexes and Buffs. There is also goes along with it is better to charge then be charge. This is obvious for some armies (Bretts, Ogres) but it is also important since you determine which models are in combat.
Looking over your categories, chaff does them all.
Harassing. The traditional role of light cavalry in the real world was exactly this. Use missile fire to cause casualties, slow down the opposition, and charge targets of opportunity (usually foragers). In warhammer this is no different.
• A poster mentioned forcing march tests. While it might be unlikely, it is still worthwhile. Forcing as many leadership tests on any opponent is a major goal of any game.
• Placing a chaff unit an inch away from an enemy unit on the flank will restrict his movement per the first point. He will have to move past the unit prior to wheeling.
• Your opponent will make a mistake (we all do, no matter how good) and expose a target of opportunity. The flank of a chariot (my cham skinks have taken down three Ironblasters in combat) or leave a charge path to an L2 caster. Having a chaff unit in position to take advantage of one of these mistakes can be critical.
• Charging a fleeing unit. Chaff are often forward and at the edge of battle, they may charge a fleeing unit to either force it to flee further (perhaps off the table or out of IP range) or back towards your lines so the main line units can run them down.
Movement Control. This is really the ability to get the charges off you want while denying them to your opponent and I include redirection in this. Let me use an example as well.
In this picture, the
WoC player is in trouble. He has 3 Iron Gut blocks bearing down on him. They are sitting at 13”. The
WoC Player is confident he can take any one but not all three or even two. If he declares a charge, he will need a 9, which is about a 25% chance. If he fails, he is in big trouble as it will be relatively easy charges for the Ogres. He only has so much space to back up. Fortunately there is a fast cav unit nearby.
The Fast cav move in the way of the three Ogre blocks. The warriors shift a little over and move up so that the over run from Ogre 2 is a ten, which is a 16% chance. Note that even if he makes the roll, you will fight on your turn, allowing you to bring magic to play. The Other 2 Ogre blocks are unable to contact the warrior block on the over run. Ogre 1 is forced to charge the rear of the fast cav and will be pointed the wrong direction, Ogre 3 is too close to maximize and will not line up an over run to hit the
WoC unit. The
Woc unit can now counter charge any one of the three units on a 6 (72% chance) if they choose not to overrun, obviously much better if they do over run but fail to hit the
WoC unit.
The use of a single 85 point fast cav unit has significantly changed the odds in favor of the slower and smaller force. Think about the force advantage the rest of the
WoC army has against the rest of the Ogre army
btw.
A bit of a simplistic example but I wanted to show one I have actually used in a tournament. There are many more tactics (double flee, forcing a clip, etc.) which is why I think it is the fun part of the game.
BTW, most players drop there chaff early, but I find it useful to drop one or two late. Better to drop it near where it will do the most good.
Hinge
