Spell overpower ability

[Skytor]

Is there a way to allow players to overpower spells,
e.g. if a fireball spell costs 25 mana, that is its minimum cost as using any less will cause the spell to fail,
but when the player is about to cast the spell they are given an option how much mana they want to use,
so if instead of 25 mana they could use 300 mana for a much stronger version of the spell,

Is this possible through events or plugins?

 

[kirbwarrior]

Without plugins, it's actually quite simple. Have the skill do nothing except cost mana and call a Common Event. In the common event, give the player a choice of how strong a spell they want (say, from four choices). Then you make a skill for each choice and Force Action the actor to use the skill.

Or, if you want a much more detailed choice, instead have the player input a number. It looks like you want the spell to be capable of failing of you don't spend enough, so don't have the base skill cost MP. Instead, have the spell be free, then call a common event that;

Inputs a number for MP cost.
If the number if higher than remaining MP, drop the number to current MP.
If the number is too low, nothing happens. Tell the player the spell fizzles (or whatever you want)
Otherwise, Force Action a second skill that's damage incorporates the variable in someway; v[10] * 2 - b.def * 3

Hope this link helps with further questions; http://www.rpgmakercentral.com/topic/36290-damage-formulas-101-mv-edition/