Players can obtain the breach enchantment for the mace in Minecraft using an enchanting table or an enchanting book. The breach enchantment allows the mace to ignore a percentage of the enemy's armor value, with each level of breach adding 15% to this percentage. Breach is most effective against armored mobs and players, with a breach 4 mace being able to kill a player with full protection 4 enchanted armor in a few critical hits. Breach is not compatible with other damage enchantments and is more suited for multiplayer PvP battles rather than single-player survival mode.