Cast spell/use skill. Design question.

[PompiPompi]

In a rogue like game. Or a tile based RPG.

How do you implement casting a spell or using a skill?

Specifically, how do you implement using a skill that enhance your next attack?
It means that after using the skill, you need to click an enemy, also it might depend on the weapon you use.

So let's say I have "Empower Sowrd", or something.
What happens if:
1) Character isn't holding a sword.
2) Character is holding a sword, but there is no enemy near by.
3) Character hold a sword, there is an enemy, but now character wants to walk instead or do something else?

Do you let the player cancel the skill and return the mana if he didn't use it?

 

[Darth Canoli]

1) Character isn't holding a sword.
2) Character is holding a sword, but there is no enemy near by.
3) Character hold a sword, there is an enemy, but now character wants to walk instead or do something else?

1. Either you can't cast the spell or it's mana wasted.
2. What about it works for the next attack with a sword (or at least within x turns then it fades away)
3. Cf. 2

 

[Norfleet]

1) Character isn't holding a sword.

Then either nothing happens and you waste the spell, or you are not allowed to cast it because it would not do anything. If there is absolutely no benefit whatsoever to simply burning mana for nothing, then you might just make it grayed out.

2) Character is holding a sword, but there is no enemy near by.

The skill will enhance his next attack with his sword. Either whenever he makes one, or until some limit on how long it lasts expires. Something like "enhances your next attack made within the next X turns". Maybe it lasts indefinitely and just stays there until he hits something. Maybe it glows and makes an ominous hum until he discharges it if he wants to hold it like that and have it give away his position until he does, if you want to somehow add a drawback to always preloading that attack.

3) Character hold a sword, there is an enemy, but now character wants to walk instead or do something else?

See above.

Do you let the player cancel the skill and return the mana if he didn't use it?

NO BACKSIES.

 

[PompiPompi]

Ok so I made "Mark Skill".
So you click a skill it "marks" it, and then when you use it, it is being activated.
Some skills might be activated immadietly though.
This is in case of a melee attack.
I should also make that any other operation that is not activating the skill, should disable the marking.
Or you can disable marking with another click.

Here is a video: