Blood pool increases with the "Generation" of the character (which, for game purposes, increases as the character advances by achieving game objectives, rather than being a set consequence of their vampiric rebirth)
Like all pools in all games; magic points, and even hit points, blood pool is a convenience, not a necessity...until it runs out. There is a wide variety of blood available for sale, however, so this is avoidable.
Having said "mere convenience", it is true that a high blood pool is so very useful. There is always a small synergy between pools and the much more important value of regeneration of health and power; having a high pool avoids overkill when regenerating, and it is more likely that all sources can be utilized without overkill. This is very true indeed in Vampire, where almost every NPC is a blood source. Although the amount of blood available for sale is infinite, there is a huge amount available from NPCs, especially enemy NPCs. And it is all free. There is no way, unfortunately, to bottle it and store it for later; the character's blood pool is the only way.
For players who are loathe to spend time saving before opening chests, and then reloading again until they get better loot, saving money on blood may be a preferable to make it through a game that has only one infinitely respawning enemy (the rat hole in the Silver Mines; low xp and no loot), and zero respawning loot chests.
There is an exploit that works in both single and multiplayer modes, that is the only way to affect the blood pool; the editor can not. When a character increases their generation, their base blood pool (the amount before any bonuses from jewellery is added) becomes the current value of blood pool at the time of level-up, plus a set bonus. The Blood Amulet, Blood Bracelets, and Blood Rings each increase the current value of the blood pool. Amulet, 25. Bracelets, 20 each. Rings, 10 each. Total, 85 more blood pool than normal, each generation, for a maximum of 340 additional blood. Easily (because it is so hard to earn money before Neonate), 255 more blood.
Cost is a factor that is somewhat rarely available for the player to affect. In Vampire, Discipline amulets, bracelets and rings are available to reduce the costs of disciplines, andthey are much more effective at saving blood than the Blood items.
And there is a way to get more xp and loot, as well. Awaken brings back enemies to be fought again for xp, and those few that are scripted to automatically drop an item will do so, as long as the character has blood to cast Awaken and can kill the enemy again.
- 5,000 XP = Neonate (+20 to bloodpool, +20 to health)
- 10,000 XP = Ancillae (+20 to bloodpool, +30 to health)
- 50,000 XP = Elder (+30 to bloodpool, +50 to health)
- 200,000 XP = Methuselah (+40 to Bloodpool, +100 to health)
The only other advantage of generation is increased hit points. Dominate skills are reduced in power compared with their Presence counterparts because they can only be used against targets of equal or lesser generation. Being able to use them is not an advantage so much as it is a removal of a handicap.
Ever wondered what happens if you put XP into Faith when Christof is a Crusader? Sadly, very little. Or you assumed it would all be wasted? Well, sort of. Put 1,325 XP into Faith, enough to raise it from 50 to 55, and Christof will receive 1,375 back when first embraced. The net effect of this is a gain of 50 XP, and it will be a little trickier to use Blood items at Christof's levelup to Neonate.