[RPG] How long does it take to learn Thaumaturgy/Necromancy rituals

"Released" means it is being conjured anywhere beyond the thaumaturge's own palm.

As per the v20 rules, the number of successes determines the accuracy of the placement of the flame. You need to declare the size of the flame (determines difficulty) and the desired placement before rolling (determines successes required).

If you want it to appear in your hand, it requires only one success. (Using anything above a palm sized flame in this case is not recommended...) Five successes means you can place it anywhere within your line of sight. It is indicated in v20 that, as a rule of thumb, you need one success per 10 yards of distance. Once the roll is successfull, there is no need for throwing or otherwise placing the flame, it immediately appears at the desired location.

When it is in your palm, it will not harm anyone including yourself, nor can it be thrown. It will function as a light and a tool to scare the crap out of other kindred. If placed anywhere else, it immediately becomes an active flame that causes damage and rötschrek. At that point, the thaumaturge no longer controls the fire and cannot quench it.

Dodging is not described in the book, but to me it seems that it can be dodged like a ranged attack if the victim has inits over the caster and knows what lure of flames is. (It's kind of hard to determine that someone is going to set you on fire if he is only looking at you.)

I'm running a game that blends VtM V20 and 2ed. In that game I have a few considerations:

For player characters I think that it should mostly be dictated by roleplaying experience more than age. If they want new rituals, it becomes a matter of finding the resources and then enough game time passing. We usually treat this sort of thing as an extended roll. For my group, this exact scenario hasn't come up because we don't have any serious magic users.

For NPCs I have two tracks. For NPCs in the city's "milieu" (which means they exist for the players to interact with but aren't major agents in the plot without player intervention) I mostly build the character according to the standard character creation rules and then give one ritual per dot in any magical path (not discipline) of equal or lesser level than the character's overall corresponding Discipline rating.

For major NPCs (those that drive the plot with or without player intervention) it's pure storyteller need. The rituals themselves are really not balanced well within or between sorcerous Disciplines, so I don't like limiting such important characters while creating them-- the builds end up too fragile to deal with players taking the story off the rails, and useless rituals are a waste. I do try to stick to the one-ritual-per-magic-path-dot, as with milieu characters, but I don't assign all of the specific rituals right away.

I'll give major characters rituals that the character "would know", in the sense that if the character regularly does something a ritual supports or makes possible, then the character knows it and this "uses up" one of the allotted rituals. The rest are fluid until they are needed. This flexibility remains until the chapter in which the players first meet the character ends (more or less), and then the rest of the fluid rituals are assigned to ones I think fit their concepts and backstories or they are lost. For high-level rituals I might require the NPC to devote resources to discovering/learning them "off camera", but that ties in with some other house systems I use.

TL;DR: The rituals an NPC knows (and their number) should support the needs of the story first and foremost regardless of any guideline. After that I aim roughly for one ritual per path dot, loosely adjusted for the NPC's access to ritual knowledge, inclination to study, and relevant Attributes, Abilities (primarily Intelligence and Occult, but others sometimes apply), and Disciplines.