Ward is a temporary shield that protects your health but decays overtime. It has no max cap and with the correct itemization and build crafting it can be used as the main defense for some characters.

The only thing that can bypass Ward and directly damage your health are traps in the Arena Echoes, however, they also cannot kill you as they deal ‘% Current Health’ damage. They can get you down to 1 hp - just like the low life gear - but something else has to finish you off.

However we are looking at this mechanic for future updates as we feel Ward should be seen as a reliable defense resource.