Counter Immunity

About Blockade, from BoardGameGeek:

Blockade is a tactical, team-based board game designed for 4 players. Teams of 2 work together to advance their Counters towards the Border and fill in their Tower squares to claim victory. Each player has a distinctive role on their team either building a formidable Offense or an impenetrable Defense. The game combines clever tactics, timely dice rolls and shifting strategies, with players swapping roles during gameplay to adapt to the evolving battle. Its Wit, Walls, and War! -description from the designer