When you start the game, you must buy items for your hero.
For example at the Sentinel side, you can buy items from all of the people and buldings around you. Same as for the Scourge side.
Additional shop are located here. #1 side shop.
#2 side shop.
Secret shop at the Sentinel side. Secret shop sell some items that does not sell at any shop at your base. You have to buy certain items here to complete your recipe.
Secret shop at the Scourge side.
To buy an item, click to any shop and click any items you wants. For example in the picture above, there are three items required. To complete the item, you must have all three items including the recipe. *Some items doesn't need recipe or any other items (core item).
Example of core item. It does not require any other items.
Example of item that does not require recipe. Just buy the three core items and it will combined together automatically.
At the end of the tooltip, the red text shows that "Orb effects do not stack" means it does not stack with other items that have another orb effect. Browse any items and you will see item that have orb effect will show the same text. So better avoid items that do not stack.
For this type of item, you can disassemble the item to turn to its basic item before it combined.
To disassemble item, click the "Circle of Power" correspond to your colour and there is an option to disassemble any item in the slot. You must drop item into it first before it can disassemble.