Rune Sword is an active item in Reverie, a mod for The Binding of Isaac.
On pickup
Spawns a random rune.
On use
Consumes the rune held by Isaac and inserts it inside the item to add a passive effect onto the sword. If Isaac does not hold a rune, a random rune is spawned instead.
Can insert up to 6 runes. Inserting a new rune while it's full will drop the first rune as a pickup.
Pressing the drop button will reorder the runes.
Rune Sword can be found in the following item pools:
| Name | Weight |
|---|---|
| Treasure Room |
1.0/1.0
|
| Secret Room |
1.0/1.0
|
| Greed Treasure Room |
1.0/1.0
|
| Greed Secret Room |
1.0/1.0
|
The following tags are applied to this item:
| Id | Description |
|---|---|
| offensive | Can appear for Tainted Lost. |
| nocantrip | Not available as card effects during the Cantripped! challenge. |
The following special synergies and interactions for Rune Sword have been documented.
| Mod | Item | Synergy |
|---|---|---|
| --- | Car Battery | Inserts the held rune and grants a random rune, or spawns 2 random runes if no runes are held. |
| --- | Book of Virtues | Spawns a rune wisp upon inserting a rune, which drops a random rune when destroyed. |
| Reverie | Lost Memory | Character: Watatsuki no Yorihime |
| --- | Reveals rooms within (3 × runeCount) distance in the map layout. | |
| --- | Grants immunity to curses. +2 Soul Hearts upon inserting. | |
| --- | Grants rock tears akin to Terra. |
|
| --- | When Isaac's bomb hits an item, it rerolls it. The item has (25 + 40 × 0.125 × runeCount)% chance to disappear. | |
| --- | Upon defeating the boss of every floor, spawns a trapdoor to the crawlspace. | |
| --- | Upon cleaning a room, spawns (5 × runeCount) Blue Flies and (5 × runeCount) Blue Spiders. | |
| --- | Upon taking damage, triggers the effect of Book of Shadows. |
|
| --- | Upon entering a room, duplicates the pickups to (runeCount) times. | |
| --- | Black Rune | +0.2 speed. +0.5 fire rate. +1 flat damage. +1.5 range. +0.2 shotspeed. +1 luck. |
| --- | Blank Rune | Inserts a random rune instead. |
| --- | Rune Shard | Inserts a random rune instead. |
| --- | Soul of Isaac | Upon entering a new room, triggers this rune's effect (runeCount) times. |
| --- | Soul of Magdalene | Upon entering a room with enemies, triggers the rune's effect. |
| --- | Soul of Cain | Upon cleaning a room, there is a 20% chance to trigger this rune's effect. |
| --- | Soul of Judas | When Isaac is being hit by a projectile or enemy, triggers this rune's effect. Can trigger up to (3 × runeCount) times every room. |
| --- | Soul of ??? | Holding a fire button for 3 seconds will spawn a butt bomb. |
| --- | Soul of Eve | Upon taking damage, spawns (5 × runeCount) dead birds in the room. |
| --- | Soul of Samson | After Isaac deals (100 + 65 × currentFloor) damage, triggers the rune's effect. |
| --- | Soul of Azazel | After clearing 4 rooms, upon entering a room with enemies, triggers the rune's effect. |
| --- | Soul of Lazarus | When Isaac is killed, consumes the rune and revives him. |
| --- | Soul of Eden | Upon inserting, spawns a random item from a random item pool. |
| --- | Soul of the Lost | Upon inserting, activates Holy Card. Upon entering an unvisited room, has a (33 × runeCount)% chance to use Holy Card. |
| --- | Soul of Lilith | Upon defeating the boss of every floor, triggers the rune's effect. |
| --- | Soul of the Keeper | When an enemy is killed, it drops (runeCount) temporary coins. |
| --- | Soul of Apollyon | Upon clearing a room, spawns (5 × runeCount) random locusts. |
| --- | Soul of the Forgotten | Upon taking damage, has a (min(50, 25 × runeCount))% chance to spawn a Bone Heart. |
| --- | Soul of Bethany | Upon cleaning a room, spawns (3 × runeCount) wisps. |
| --- | Soul of Jacob and Esau | Upon inserting, spawns a clone of the passive item with the highest quality from Isaac's inventory. |
| Reverie | Soul of Eika | When an enemy is killed, it has a (min(20, 5 × runeCount))% chance to spawn a friendly Blood Bony. |
| Reverie | Soul of Satori | Tears have (50 × runeCount)% chance to turn enemies friendly. |
| Reverie | Soul of Seija | Grants Seija's passive effect. Inserting reversed Soul of Seija
cancels the nerfs for high-quality items. |
| Reverie | Soul of Hourai | Activates the effect of this rune at the start of every floor. |
| Reverie: Make Good Omissions | Soul of Flandre | Displays the 'eye' of every enemy or trap upon spawning. Enemies that display ''Eye'' take double damage. |
| Reverie: Make Good Omissions | Soul of Reimu | -50% hitbox size, now indicated by a red dot near Isaac's legs. Some enemy shots pass over Isaac. |
* Note that not all possible synergies and interactions are listed here.