This idea was inspired by Kyle Smith from the Tower Defense Ideas thread.

In a traditional tower defense game you build an assortment of special effects towers around the map. Some towers are strong against flyers, others slow creatures down and some do splash damage. A lot of times 2-3 specialty towers placed in a tight proximity can make a lethal combo.

This system has proven to be extremely popular, yet it lacks flexibility. In order to modify your strategy halfway through a game you are forced to sell towers at a reduced price. The more towers you sell the less efficient your defense is. It is generally best to plan out your entire defense before you ever build a tower in order to prevent waste. I’m not saying it is a bad system. I personally quite like it but there are other options.

I would like to see a system where you have the option to build component towers that are basically a shell of a tower with the capacity to harbor various implements of war. A basic component tower may have 4 slots. You could hire 2 archers, a cleric and a wizard to fight from the tower. They would each gain experience and eventually become increasingly more powerful.

At some point in the battle it may make sense to reorganize your towers. One example might be in a multi-path TD where creatures try to take the path of least resistance. If you have towers along a patch that are suddenly only encountering 10% of the wave then it makes sense to move some of your characters to component towers along another path.

It would also be possible to allocate resources to give your apprentice characters an experience boost. So if you have 1 tower with 4, lv10 archers and another tower with 4, lv1 archers that wouldn’t be very efficient because it would take a long time for your lv1 archers to gain experience. A much better scenario is where you have a tower with 2, lv10 archers and 2, lv1 archers so your lv10 archers can train your lv1 archers.

When you upgrade a component tower it simply increases the capacity. Maybe you add 1-2 slots per upgrade.

Now for the components, items, artifacts, gems…whatever you want to call them. Instead of having a boss level every 5-6 waves why not have a boss mixed in with every wave. If you kill the boss he drops an item that you can plug into one of your component tower slots. These items could be random, sort of like Diablo 2 or they could be static to make the game a little more strategic and a little less luck driven.