I've come upon a really interesting design issue while creating a magic-centric battle system that doesn't require the player to spend any resources (such as MP) to use skills. The design so far has used Cooldowns as a way to gate the frequent use of powerful skills, rather than MP costs. The more powerful the skill, the longer its Cooldown (the number of turns before you can use that skill again). This approach offers a lot of benefits - for example, it allows the player to use skills without worrying about saving resources for later battles, and the use of Cooldowns (even short Cooldowns for weaker skills) also prevents spamming the same action over and over, which would be boring. This seems to work well for extended Boss battles which generally take 10-20 turns to complete, but normal Encounters need to be much quicker to avoid the feeling they are "dragging on" - I've often heard 3 turns as a good length for challenging normal Encounters. Longer Cooldowns become kind of irrelevant when the battle lasts just 3 turns - a 6-turn Cooldown might as well be a 3-turn Cooldown (and therefore doesn't serve to balance out its higher power). For skills used near the end of the battle, the Cooldown becomes completely irrelevant. I've thought about having Cooldowns persist between battles, but that might serve to encourage the player to draw out battles that are already decided by spending turns doing nothing before finishing off the final enemy. Can you think of any way to design Cooldowns as a balance against skill power that still serves its purpose in shorter battles? And do you feel that Cooldowns can be used as a "cost" for skill use in the complete absence of MP and other resources, or is the entire concept broken?