4
You can really tell that they wrote parts of the module before publishing the rules…
(ttrpg.network)
For reference: There is a duell in the module where a shaman tries to secretly help one NPC by continously casting Cure Wounds on him while supposedly only helping him "stand up" after he intentionally let‘s himself fall prone. To spot this, a PC has to specifically declare checking for interventions a then suceed a DC 15 perception-check despite being within earshot…
I love this gem. The only thing they got a but wrong is that Bardic inspiration could actually be whispered, since it only requires the target to be able to hear you.