Strength

Strength is the Warrior primary attribute. It gives 1% armor penetration per attribute level when using attack skills. It also has the secondary benefit of enhancing Strength based skills, which mostly relate to doing damage or surviving.

Strength is a requirement for some shields. There are also shields that require Tactics.

Secondary Warriors do not have access to Strength.

Even if a Warrior does not utilize any Strength skills, it's recommended that any spare points be placed into Strength, if only for the purpose of dealing a little more damage when using attack skills.

Much like other classes primary attributes, having points in Strength is not required to have an effective warrior or tank but many skills do help in makeing one.