You need to examine what the positives of your class are against the negatives of the resto Druid. There’s a few glaring weaknesses for a resto Druid. The biggest in Arena matches is the prevalence of burst damage. This is why resto Druid’s have been used less in 5v5 play. They simply can’t handle the big healing necessary as effectively as other classes.

With the introduction of Resilience to gear and the smaller team sizes in the 2v2 and 3v3 brackets, Druid’s can effectively keep their teammates healed with Lifebloom, Rejuvenation and occasional Regrowth. However, teams with good coordination and damage output can fool resto Druids by target switching and droppinig burst damage.

In the end a Druid’s make or break is his ability to spend more time casting its various crowd control abilities rather then healing. If you can force a Druid to spend more time healing then crowd control, a fight becomes much easier.

If you decide to focus damage on the resto Druid then beware of their many abilities. Nature’s Grasp, Barkskin and shapeshifting give them a last line of defense if their crowd control doesn’t keep you off them. In order to successfully kill a resto Druid you must catch them in Caster Form with Barkskin on cooldown. The combination of extremely high damage and well placed stuns or fears can kill them.

At the end, it all depends on the skill of the resto Druid. Many resto Druid’s claim they are “un-killable” including in 1v1. With the many talents and spells at their disposable it’s hard to argue with them if they use them in the right order. Beating a resto Druid comes down to forcing them to make a mistake with cast order and position. If you don’t know they made a mistake though it’s hard to understand how to capitalize on it. Learning what Druid’s are capable of is the first step to beating them.