Overcoming arachnophobia slowing effect doesn't stack with itself

Why would it? It'd be overpowered if you could bring mobs to a standstill, ignoring freeze and sleep resistance and not freeing them when hit.

Edited August 29, 2022 by Bumber64

It wouldn't be because of books casting time, sanity, durability cost as well as occupied inventory space. If player has speed to create enough distance between mobs and player themselves to cast double web, that player would very likely be able to outrun mobs completely. If player plans in advance and is able to kill the hord within 2 minutes as well as fight 4 shadows/spend extra resources to restore sanity one would very likely be able to kill those mobs without stacking effect. If player is even considering to use book at this point as opposed to bringing other helpful tool in that inventory slot, such as magiluminecence, beefalo with bell (glossammer/war saddle if one is already on a beefalo), pan flute, sleepy time stories, on tentacles (works fine even without overcoming arachnophobia), extra armor, moggles (allows to avoid creating dangerous hord and see potential environmental help easier), bramble husk from friendly Wormwood or Bernie from friendly Willow, etc. And book doesn't even work by design in cases where is would be most useful - on Dragonfly + enraged form, grumble bees and 3rd phase of Celestial Champion.

Also it's not like mobs are defenseless and are turning into their drops on casting: one would still need to kite their attacks in order to kill, which is tricky with group of splumonkeys, for example. Plus book durability cost is still there, stronger effect would mean less times it can be used before need to recharge book.

Which is why I see no harm in restoring consistency of speed buffs/debuffs DST follows (multiplicative) to this book.

I wonder if you would consider shadows not triggering spider webs being overpowered and Webber's nerf. Same question to you about moleworms triggering spider webs and fix of this bug.

Edited August 29, 2022 by Pig Princess

The shadows spawned from reading would themselves be subject to the stacked slowing, which is a major part of my point. Imagine if sleepy time stories worked on shadows.

Funny you should mention Webber, because spider den webbing doesn't stack with itself, and there's no expectation it should. You're stepping on webs or you aren't. Seems clearly not a bug.