Halflings are notoriously hard to get a grip on, and they can easily evade even the most tenacious of pursuers. You can spend Willpower Points in combat to avoid being hit by physical attacks (see Chapter 5). Every WP spent eliminates one x the attacker rolls.
I had no halfling PC at my table yet, but the description made me wonder WHEN the player during a melee sequence must decide to intervene? Hard to Catch is used to "buy away" enemy successes when they attack. It is, however, not clearly defined WHEN the player must make this decision, unfortunately, there is room for interpretation. It is NOT clear whether the player must immediately decide to take action after the enemy has rolled dice to reduce the attack value, or if the player can wait for their own defensive action to augment that later. I am inclined to go with the first interpretation, though, because the description explicitly states that Hard to Catch (only) buys away attack successes per WP spent on a 1:1 basis, up to zero.
But that's me. Other opinions, interpretations, or handling?