The Spider Staff is a Hardmodesummon weapon. It spawns a spider minion that follows the player and attacks by latching on to enemies. If enough of them attack the same enemy, it can be stun-locked. The spiders inflict the Acid Venomdebuff for 2-4 seconds, can climb background walls, and jump high. Like other minions, the summoned Spider is invincible and follows the player for an unlimited amount of time, unless the player dies, summons a replacement minion, cancels the buff, or leaves the world.
Its best modifier is Ruthless. The Mythical modifier provides the widest array of stat bonuses, but these primarily affect the initial summon rather than the resulting minion. Additionally, minions cannot deal critical hits. The only lasting advantage a Mythical Spider Staff has over a Ruthless one is knockback.
Unlike most minions, a spider only takes up .75 of 1 minion slot. Therefore, with 3 potential minions, 4 can be summoned, and with 6 potential minions, 8 can be summoned, etc. This can be especially useful if the player wants a larger pack of summons rather than a more powerful one.
Testing has shown that if there are only 3 whole slots available, only 3 spiders can be summoned. Attempting to summon a spider when there is only 0.75 of a slot available will fail. This means that, with the largest possible total minion count of 11, exactly 14 spiders can be summoned.
Due to the spiders' damage being classified as piercing, it can cause enemies to be immune to other piercing attacks. This may prolong fights against enemies with higher health while the spider minions are in use.
The spider minion's ability to move freely on background walls makes it much more effective in areas with good wall coverage. It is otherwise limited to walking and jumping, and since it cannot fly (for the purposes of attacking) and has no projectile attack, its effectiveness is limited against flying enemies.
The Spider Staff is easily acquired when first entering Hardmode, as most players will have already found a Spider Cave before it begins. Simply return there to kill the Black Recluses that begin spawning in Hardmode. Black Recluses hit hard and can take a while to defeat with pre-Hardmode equipment, but the effort is worth it.
The Spider Staff has the highest base DPS of any pre-Plantera minion.
However, the Spider Staff's lack of local immunity caps the hit rate of a hoard of spiders at 6 hits per second. Since spiders tend to clump up on one enemy, this makes any more than 3 spiders redundant. The player can use other minions alongside the spiders if they have more than 3 minion slots.
Although the game does not allow the player to summon 4 spiders while having 3 whole minion slots available, if the player summons more than 3 spiders through other means (e.g. Bewitching Table) and then has their maximum minion slot count reduced back to 3, the player will keep 4 of their spiders as originally deserved.
If several spiders latch onto a single target that can receive knockback, the target will often be carried away from the player, but in some cases can carry the enemy towards the player faster than the enemy itself could normally approach.
Each time the spider is summoned, it has a random one of three possible sprite graphics. The first is an unidentifiable purple spider, the second resembles a Mexican red knee tarantula, and the third resembles a black widow. They are all functionally identical.
The different types of spiders are summoned in order, rather than randomly.