Variable Costs Flatten Gameplay

In Mage Wars, counter-spells cost "X" mana. For Dissolve, X is the cost of the equipment you destroy; for Dispel, it is the cost of the target enchantment. The appeal of varying the cost of an action based on its outcome is obvious, but it is a mistake. In balancing it, you remove the texture that made the action interesting in the first place.

Texture in games gives players something to learn and improve at. Learning when a choice is stronger or weaker is a large part of what makes games fun and replayable. Variable costs trivialize this because using the action is as good in one context as in another. With fixed costs, you must decide whether it is worth doing something; with variable costs, you can assume it will be.

That doesn't mean that Mage Wars counterspells are entirely flat. Since you have a limited number of each spell, you do still need to decide what to use them on. This is still much weaker than it could be if costs varied within the mana-economy subgame.

Variable costs flatten gameplay to the degree to which they match the outcome. If rewards don't rise linearly with costs, there is no problem. Ticket to Ride requires larger sets of cards for longer routes, but they score escalating numbers of points. Longer routes are disproportionately valuable, especially since they are more action-efficient. Even if the game awarded points linearly, building routes would still have texture because of tickets.

Balance and texture are often at odds. It is so easy to smooth a game until nothing interesting remains. Variable costs are tempting because they make balance easy, but they are a trap. They not only remove opportunities for player growth but also shrink the design space. It is hard to compete with the optionality of an ability that scales to fit the challenge.