From publisher blurb:
For as long as we've been gaming, heroes have ventured out and cut their teeth on the various humanoid tribes in an attempt to make a name for themselves and get rich. Now the tables have turned, and it's the goblinoids chance to get revenge.
This version of X1 is designed for use to be compatible with D&D™ 5th edition, for 4-5 characters of 1st level. The scope of this adventure is meant to be a few-session break from your current campaign, to play as the monsters for a neat change of pace. While it can be part of a greater campaign, it has not been designed as such, and thus may be a bit linear in design.
X1 is the first adventure of a two part series, with X2 Payback bringing conclusion to this adventure path.