5e Homebrew: Feat: Mana Weaver

Inspired by the rapidly-becoming-canon inclusion of the MTG multiverse in the D&D planescape cosmology, I have finally come up with a solution to a long-standing design problem I've always had. See, I've always loved the spell points variant rule in the DMG because I thought it would be an interesting way to effectively double the number of types of spellcasters in the game. However, there were two fatal flaws with my infatuation.

1. Spell point casters are significantly more powerful than normal casters as the rule is written.
2. There is no fluff justification for what differentiates a points-based wizard from an ordinary wizard.

Luckily, I've found a single solution for both! I have made access to the spell points variant rule gated by a feat with the requirement that the character have the spell casting class feature.

The flavor of the feat comes directly from Magic the Gathering. In MTG, spellcasters manipulate a metaphysical quantum particle, called mana, which forms the substrate of the background magical field. Mana IS spell points. D&D spellcasters don't understand magic on this fundamental of a level, interacting with magic indirectly through rituals and superstition. It's like the difference between alchemy and chemistry. Theoretically, if the MTG lore is being incorporated into D&D, that must mean that there is some way for a character to cross that boundary and become a mana weaver like the more advanced spellcasters in the broader multiverse.

Hence a feat! A character usually can't get a feat until at least level 4 anyways, unless you allow the variant human.

The next problem was the power difference. This was a pure numbers problem. Let's look at the spell that most strongly exemplifies the difference. At level 5, wizards gain access to fireball. A standard level 5 wizard can cast fireball twice in a row. A level 5 spell points wizard can cast fireball 5 times in a row. The part you aren't seeing is that the standard wizard can still cast 9 other spells, while the spell points wizard has pretty much spent themselves out, with only a few points left for maybe a first level spell or two. It almost balances out, but the spell points wizard is clearly advantaged because if he really needed to sling 5 fireballs, he can, while the standard wizard is stuck at 2.

To counterbalance this, I targeted power output rate. The spell points wizard can put out more power with the same resource than a standard wizard if they optimize their resource use. The problem is that the spell points wizard can convert all of their spell points into just one type of spell slot and then cast the same spell turn after turn. The rate they put out more power is impressive. So I cut it in half. By making the conversion of spell points into spell slots require an action, and by limiting the rate to one spell slot at a time, I make it so there is a clear cost to their extra power. I also made it so that converting spell points counts as casting a spell (so anything that triggers on the casting of a spell is activated by it) and sheds dim light for flavor purposes. Finally, to stop a player from pre-making all their slots, I made it so that artificial slots are unstable and dissipate at the end of their next turn. This idea is taken directly from MTG. Mana burn was a rule that any unspent mana at the end of your turn would disappear and hurt you. I'm not sadistic, so I dropped the burn part of mana burn.

So, under this feat, the level 5 wizard can cast 5 fireballs in 10 turns.

Here's the feat:

Mana Weaver

Prerequisite: Spell casting class feature

You have studied the most fundamental behaviors of the weave and uncovered something incredible: the weave is composed of a metaphysical substance that can be manipulated directly! This material, called mana, forms the background magical field commonly called "the weave". By manipulating points of mana directly, it is possible for a person to convert magical power normally limited in potential form into other types of power virtually at will. This discovery has completely transformed the way you practice magic.

You use the spell points variant rule in the dungeon master's guide, with the following additional rules:

• To convert spell points into a spell slot, you must spend an action. This action counts as having cast a spell and gives off dim light in a radius of 5 ft for 1 round.
• Spell slots created from spell points are unnatural, and thus are unstable. A spell slot made from spell points disappears at the end of your next turn if it has not been spent to cast a spell.