Increases your block value by X% and damaging melee and ranged attacks against you have a 10% chance to increase your chance to block by Y%. Lasts 10 sec or 5 blocks.
Redoubt is a talent in the Protection tree, you will need to spend 3 points in Protection to max it.
Block Value Increase
Block Chance Increase
It is not adequate to rely on this skill to be uncrushable, as it procs off randomly.
For uncrushable tankadins, the extra blocking from Redoubt is useless when tanking a single target. However, during AoE tanking, where Holy Shield is sure to expire quickly, the frequent Redoubt procs help mitigate significant amount of damage.