Java Edition 1.9.1-pre1

1.9.1-pre1 is the first pre-release for 1.9.1.^[1]^[2]

Additions

New armor attribute: generic.armorToughness.
- Damage formula is now $t o t a l D a m a g e = d a m a g e \times (1 - \frac{m a x (\frac{d e f e n s e P o i n t s}{5}, d e f e n s e P o i n t s - \frac{d a m a g e}{2 + \frac{t o u g h n e s s}{4}})}{25})$ , i.e. increased toughness means less armor defense point reduction from strong attacks.
- Diamond armor has toughness 2, all other armor has toughness 0. A full set of diamond armor, therefore gives a toughness attribute of 8.
New option enableWeakAttacks in options.txt.
- Defaults to false. When false, the client will ignore attempts to attack when weapon cooldown is less than 75% recharged.
- The effect was removed in the final release, however the option itself remains.

Added sound effects, while gliding in the Elytra.
- Sound event item.elytra.flying.

General

Entity selector c (count) now sorts on proximity using true coordinates, not coordinates snapped to the grid.^[3]

Combat

Missing an attack no longer triggers the weapon cooldown (later reverted in final release.)

Now also work with dispensers and droppers.
- Dispensers with arrows in jungle temples now use loot tables.

Session IDs

From released versions before 1.9.1

MC-7961 – Hopper can't fill or empty a chest if the chest is blocked from opening.
MC-56162 – Setting /worldborder damage amount 0 doesn't work.
MC-95352 – Spatial target arguments c, dx, dy, dz behave unexpectedly and inconsistently.

From version 1.9

Other fixes:

Fixed game engine adding non-existent entities (failed mob spawns, etc.) to its internal lists, increasing instability.^[5]

Video made by slicedlime:

This version was previously removed from the launcher for some time, but was added back in September 2018.