Build A Spell

Fill rises again. Last release stopped it reaching through walls, but its reach limit ended up acting as a wall of its own: a fill that ran out to that limit was read as a fill that had spilled into the open, so a room wider than the limit got one flat layer across its floor and nothing above it. Running out of reach no longer ends a cast: the limit simply marks the edge of what one cast can touch, and a fill that is still enclosed carries on rising through it.

Alongside it: Conjure builds with the block in your off hand rather than whatever you happened to be aiming at, Fortunate Son raises the Looting level of the loot roll itself instead of multiplying the finished drops, and Echo and Double are priced against the spell they repeat instead of at a flat fee that was a small spell's entire budget and a rounding error on a large one.

Supports: Minecraft 26.1.2+ (Java 25) · Minecraft 26.2 (Java 25) · Minecraft 1.21.1 exactly (Java 21)

Fill

• Running out of reach no longer ends the cast. The limit was read as the edge of the space itself, so a layer that ran out to it counted as one that had escaped into the open and the cast stopped where it stood, leaving a large hall with one flat layer across its floor and nothing above. Reaching the limit now only stops that one layer spreading.
• The reach limit is a distance in every direction, and a cast has a budget. The reach runs thirty blocks out, up and down from where the spell landed, and one cast places 4,096 blocks at most. A hall far wider than the reach fills as much of itself as one cast can carry rather than the whole of it. Both are server-configurable.
• Fill decides it has reached the surface by what is overhead, not by how far it got. A layer that merely ran out of reach might still be held just out of sight, so Fill looks up instead. A ceiling only counts if the fill could rise to meet it, which is what separates an enclosed hall from the open Nether and its bedrock a hundred blocks up. A hole in a roof is plugged on the way past, and leaves are not a roof at all, so a fill cast under a tree places nothing.

Conjure

• Conjure builds with the block in your off hand, and never uses it up. Hold cobblestone and it builds cobblestone, hold deepslate and it builds deepslate, and one block will build all day, because mana is the whole cost. It used to copy whatever block the cast happened to land on, so the material changed with your aim, and casting into open air gave you no way to ask for a particular block at all.
• Conjure builds with common ground material only. Stone and its variants, dirt and grass, mud and clay, sand and gravel, sandstone, terracotta, calcite and dripstone, and the nether and end equivalents. Hold nothing, or hold something with a price on it, and you get stone instead. Anything Conjure builds with is made out of mana and so has to be free and endless: that is why no ores, metals, gems or obsidian are on the list.
• What Conjure may build with is a block tag rather than a config setting. A datapack can add its own stone types to #buildaspell:conjurable, and modded stone that already carries the vanilla stone tags is covered without anyone having to list it. The old conjureAllowedBlocks setting is gone: it matched a block's full name against a list that shipped with bare names in it, so out of the box nothing ever matched.

Fortunate Son

• Fortunate Son now raises the Looting level of the loot roll itself. It used to multiply the finished drops after the fact, which copied things a loot table never meant to multiply: a Wither's nether star, a mob's equipment, anything that drops as a certainty rather than as a roll. It now increases only what vanilla would let Looting increase, and a weapon already carrying more Looting than the spell grants still wins. Reap does the same on the farming side, handing the crop's loot table a Fortune level instead of growing the finished harvest.
• A bare-handed cast grants Looting exactly as an armed one does. Feeding a Looting level into the roll means the game has to ask the caster's weapon about it, and an empty main hand has nothing there to ask. Fortunate Son puts a stand-in weapon there for the length of the roll and takes it away afterwards.

Balance

• Echo and Double are priced against the spell they repeat rather than at a flat rate. Each is charged four fifths of whatever the rest of the spell costs, and stacking compounds rather than adds, so two come to a little over three times the spell on its own. A fixed price had them backwards: forty mana was more than a small spell cost in total and barely a tenth of a large one. Both carry a totalCostMultiplier in modifiers.toml, and a server still holding the old flat fees is moved off them at first world load.
• Stacking one modifier onto one effect costs more with each stack. The second copy of a modifier on an effect is priced above the first and the third above the second, so piling one modifier onto one effect gets expensive while spreading it across a spell does not. Each effect counts on its own, and the modifiers attached to the delivery form one further group of their own. How steeply the price climbs is server-configurable, and setting it to 1 restores flat pricing exactly.
• Sunder raises the spell's damage rather than adding damage of its own. The flat figure it used to add was worked out from the target's armor and took no notice of what the spell was doing: against a foe in full diamond a single Sunder added ten damage to a spell whose entire hit was two, and copies stacked without limit, so a handful of them killed an armored player outright. It now multiplies the damage the spell was going to do anyway, by an amount that follows how heavily armored the target is, and however many copies you attach it stops at three times that damage.
• Fortunate Son stacks as far as you can pay for, rather than stopping at three. The old cap did not stop you adding a fourth, only stop it doing anything: you were charged for it in full and got nothing back. The price is the real limit now, and a steep one, since each Fortunate Son costs half as much again as the one before it and a fourth costs over three times what a single one does. The cap survives as a backstop at twenty-five, far past what any mana pool will carry.

Spell Builder

• Component tooltips quote the price you will actually pay. A placed component now reads its cost out of the spell's real price breakdown, and a palette entry quotes what dropping it in would add to the total. Both used to quote the component's base price, which took no account of the escalating cost of repeats or of any server cost setting. Datapack-added effects are priced properly on a server too, where a client has no copy of the definitions they are priced from and counted every one of them as free.
• A long chain scrolls sideways. Modifiers extend their effect's row to the right rather than wrapping, so a heavily modified effect ran off the edge of the build area and everything past the edge was simply invisible. The build area now carries a scrollbar along its bottom, and the chain moves with a sideways tilt of the mouse wheel, or with the wheel while shift is held.
• A spell may hold a hundred entries, up from thirty. The limit applies to each of a spell's two lists separately: the effect chain and the modifiers attached to the delivery. maxSpellComponents in general.toml lets a server set its own figure, higher or lower. Mana is still what decides how large a spell you can actually afford to cast.

Iron's Spells 'n Spellbooks

• Build a Spell can run on Iron's mana. With both mods installed, each keeps a mana pool of its own: two bars, two unrelated refill rates, and gear that raises Iron's maximum mana raises only Iron's. On the 1.21.1 build, turning on deferManaToIronsSpellbooks in general.toml makes Build a Spell spend out of Iron's pool instead of keeping its own. Iron's then sets both the size of the pool and how fast it refills, so the Arcane Altar stops offering the Mana Pool and Mana Regeneration enchantments, which would have nothing left to act on. Spell Power is unaffected, and the setting is off by default.

Fixes

• Summoned creatures arrive armed and leave nothing behind. A skeleton's bow and a vindicator's axe are handed out as part of spawning one the ordinary way, a step a summoning spell never took, so both turned up bare-handed and fought with their fists. Skeletons now come as a mixed host, roughly half archers and half swordsmen, and vindicators carry the iron axe they are known for. A summon is conjured out of mana, so it drops neither loot nor experience nor the weapon it was given: the Iron Golem was the worst of it, handing back ingots and poppies for a spell you could simply cast again.
• The Tracking delivery holds a single living target. Its projectile steered toward the nearest entity of any kind, and a dropped item is an entity as much as a creature is, so anywhere lived-in it would break off and chase the litter on the floor. It also picked its target afresh every tick and gathered pace each time it corrected. It now takes hold of one living target and keeps it until that target dies, is struck, or leaves range, and it turns toward it while holding the speed it was fired at.
• A large spell is saved whole. A spell keeps two lists, the effects with their own modifiers and the modifiers attached to the delivery, each with a limit of its own. Saving one sent both as a single list, and the server measured that against the limit meant for the effect chain alone, so the end of the chain was dropped to fit. Nothing said so, and the builder kept showing the spell you had built because it remembers your last layout, so the missing pieces only appeared the next time you logged in. The builder now turns down a component past the limit and tells you.
• A full mana bar reads as full. Your mana is sent to your client once a second, and only when the figure has changed, but the comparison was against the figure at the start of that same second rather than against what your client was actually holding. Mana almost always finishes filling somewhere between two of those moments, so the last step of it was never sent and the bar came to rest a second's regeneration short of the top. The server always had you at full.
• A stack of Blank Runes fills one rune at a time. Essence is recorded on the stack rather than on each rune, so a slot holding several of them shared a single counter: the whole pile appeared to charge together, then one rune transformed and the rest were left sitting at full with nowhere for their essence to go. The rune being filled is now taken off the pile before it gathers anything, and runes left stranded at full by an older version are cleared one at a time until the backlog is gone.
• Installing on the wrong Minecraft version is refused rather than crashed. The 1.21.1 build declared itself good for everything below 1.22, so it loaded on 1.21.2 and later and then died part-way through startup: on a block id the game now demands, on a NeoForge event that has since been removed, or on a class that had moved out from under it. It names 1.21.1 exactly now, so a newer game stops at once and tells you which version the mod wants.
• On Minecraft 26.2, Duration lengthens a summoned host again. Skeletons and vindicators read their lifetime straight from the server setting and ignored the Duration modifier entirely, so a spell built to hold them longer held them for exactly as long as one built without it. Vexes were unaffected, and the other Minecraft versions were never affected.
• The Arcane Altar enchants past level twenty. Its three enchantments were built to run to 255, as high as a level is stored, and the creative tab and the guidebook both said so. The altar itself refused anything above twenty: the selector would not offer a higher level and the server turned the request down. The per-enchantment settings in general.toml were never that limit. They cap how far a level keeps scaling the bonus, not how high one may be bought. The cost curve needed no change, having already charged netherite by the level past fifteen, so the climb is limited by what it costs rather than by a cap.
• The creative search no longer carries hundreds of Build a Spell enchanted books. Spell Power, Mana Pool and Mana Regeneration each run to level 255 so the Arcane Altar always has room to keep enchanting, and the search tab files one book for every level of every enchantment: that is 255 books apiece. Each now appears once.
• Build a Spell's menus no longer look blurred. Every centred heading carried a drop shadow, which lays a second copy of each letter a pixel down and to the right; at the size these panels use that reads as a smear rather than as depth. Centred text is flat now on every screen, and the panels no longer blur what sits behind them. The labels around the spell ring keep their shadow, since those sit over the world rather than over a panel.

Documentation

• The guidebook and the component reference are brought up to this release. Fill's pages give the reach limit and the per-cast budget and say that running out of reach stops a layer rather than the cast; Conjure's give the off-hand rule and the tag; Echo's and Double's quote a share of the spell rather than the old flat forty and fifty; Sunder's describes a multiplier that levels off; Tracking's says the projectile takes hold of one target and holds the speed it was fired at; and the Summon pages say that skeletons arrive with a bow or a sword and vindicators with an axe, and that a summon leaves nothing behind.
• The mana-cost pages price repeats. They described a spell's cost as the base prices added together, which stopped being the whole story some releases ago. Each further copy of an effect is charged half again as much as the one before it, a modifier is counted against the effect it sits on rather than against the whole spell, and Echo and Double take a share of the total rather than a price of their own. The read-me, the documentation home page and the configuration reference say the same, and the configuration page no longer lists a Conjure block list.
• The guidebook reads the same on every Minecraft version. One version's copy of the book had fallen a long way behind the others. It printed the exact recipe for every combo instead of leaving them to be discovered, described a Cast Speed attribute that does not exist, promised a Recall that reaches across dimensions when it has never done so, said that Nullify stops Slowness and Weakness when it stops neither, and had the Rune delivery waiting to be stepped on rather than counting down. Every page of it now matches.
• The cross-mod reference, the read-me and the Geyser page are corrected. The cross-mod reference gave mana regeneration as a figure per tick when it is per second, a twentyfold difference for anyone building against it, and was the one file still carrying the mod's former name. The read-me named five of the seven delivery methods two lines above a list that counts seven. The Geyser page called the combo a mobility tool, though the eruption never lifts its own caster, and did not mention that it damages what it throws.
• The cross-mod reference now teaches casting, and the configuration reference is complete. The read-me promised a public casting API that the reference never mentioned: it now walks through building a spell from ids and casting it on another mod's own resource. Its attribute notes had two errors: they said a duplicate modifier is ignored when it in fact throws, and gave a stacking formula that added where the game compounds. The configuration reference gains the eighteen settings it never listed, rune progression and portals among them, and the guidebook no longer claims the config can cap what level the altar sells: those settings only cap how far a level keeps scaling.
• A few claims about numbers are straightened out. Spell Power never touched a spell's mana cost, whatever three pages said: the only cast-time discount is a held wand, which is read from either hand with the better wand winning. Sanctuary's page now says its blessings cap at level III, and the mana pages note that a server may hand the whole pool to another magic mod, at which point the altar stops offering the two mana enchantments.