PF2e Reaction Checker updates Foundry, flags available reactions in combat

Missed reaction windows are one of the easiest ways a Pathfinder 2e encounter goes sideways on Foundry. PF2e Reaction Checker tackles that exact problem by lighting up when an actor can spend a reaction, so a table moving fast does not overlook the moment an Attack of Opportunity, Shield Block, or similar trigger actually opens.

The module’s Foundry listing puts that promise in plain terms: it is a small module, built for Pathfinder Second Edition, and the latest version shown is 8.1.2. It is tagged under Automation Enhancers and Combat Enhancements, and the page lists compatibility from Foundry Virtual Tabletop 10 through 14.999, with verification on Foundry 14.360. The available-versions history shows older releases including 1.4.1 and 1.3.1, while the author name on the listing is Reyzor.

That small footprint matters because PF2e’s reaction rules are strict. You get 1 reaction per round, you can use it only when the trigger occurs, and the GM decides whether reactions are available before a creature’s first turn begins. In practice, that means the timing layer can be just as important as the damage roll. A visible alert in the interface does not change the rules, but it does make the rules harder to miss when several creatures are acting, conditions are stacking, and the table is trying to keep initiative moving.

The GitHub repository adds more texture to what the module has become. The project, titled “Module for the foundry vtt pf2e system,” showed 216 commits, 8 forks, and 5 stars at the time of capture. Its README describes grouped messages, homebrew reactions, multiple reaction handling, and Recall Knowledge support. It also points to planned or known issues, including recall-knowledge labeling by creature type and lore DCs, Nimble Dodge spam notifications with area spells, and frequency-once-per-day handling. That is a sharper profile than a simple notification tool: it is a rules-facing utility built to surface the combat options that are easiest to forget.

The broader Foundry context makes the fit even clearer. The Pathfinder Second Edition system is a volunteer-developed project supported by an official partnership with Paizo Inc. and Foundry VTT, and PF2e Reaction Checker slots into that ecosystem as a quiet but practical layer on top. When a reaction is available, the module makes sure the table sees it before the window closes.