PHBs

PHBs is an acronym with multiple meanings across different fields. The two most common uses are in gaming contexts and materials science, but the term can appear in other domains depending on the context.

In tabletop role-playing games, PHB commonly refers to the Player's Handbook, a core rulebook for many editions of Dungeons & Dragons. The PHB contains details on character creation, class features, spells, equipment, and core mechanics. In the 5th edition, the PHB is one of the three core rulebooks, alongside the Dungeon Master’s Guide (DMG) and the Monster Manual (MM). The phrase PHBs may be used to refer to more than one edition or to multiple copies of the handbook.

In bioplastics and polymer science, PHB stands for polyhydroxybutyrate, a biodegradable polymer in the broader family of polyhydroxyalkanoates. PHBs are produced by certain bacteria and can be harvested as thermoplastics. They are valued for their biodegradability and compostability under industrial conditions and are used in packaging, disposable items, and some medical devices. Properties vary with crystallinity and copolymer composition (for example, PHBV is a copolymer with hydroxyvalerate). Drawbacks include relatively high cost and limited heat resistance compared with conventional plastics; processing often requires controlled conditions.

Other uses of PHB/PHBs exist, depending on context. Without context, the meaning of PHBs can differ significantly.