There are 3 clubs in the game if I'm not wrong.
- The basic club you can buy to the tieffling blackmith inside the druid grove
- The Club of Hill Giant Strenght in the arcane tower
- A basic club with another skin (and maybe a name) when you fight the wooden creatures in the swamp.
That's the only 3 I found but some ennemies may also have one.
It's interresting to shillelagh 2 clubs while dualwielding.
When I tried that, it only applied shillelagh to the club in my main hand.
Better to cast flame sword, then move the flame sword to the off hand with the club in the main, then cast shillelagh. The flame sword does the same damage in either hand.
