The unit may gain one of two different sets of effects depending on whether it shows up Sober or Drunk on the Battlefield. At step 8 of the Pre-Game Sequence (after Spell Selection) the player must choose whether a Drunkard unit is Sober or Drunk. Drunk Characters cannot join units containing any Sober models and vice versa (models without Drunkard are considered neither Drunk nor Sober).
Sober
The model gains Light Troops and Vanguard. A unit that has been Sober once loses Scoring for the rest of the game. If playing Capture the Flags, Scoring is not lost.
Drunk
The model gains Devastating Charge (+1 Str, +1 AP) and Fearless. Drunk units cannot Ambush.