If you started with a 1st character, and have enjoyed the wilderness expansion of Expert level play, then you are ready for this set.
You can also use this set if you'd like to discover what it's like to own a medieval castle. You can rule a land, bring civilization to the wilderness, and cope with all the threats to your territory, while facing monsters and magic of all kinds.
Your adventures will be different than ever before. Lower level characters must keep busy surviving and learning; but when you find the challenges lacking, or treasure too easily found, you may start to wonder?"Is there anything more?"
There certainly is! Games for higher level characters are often different?as new as when the characters first braved the unknown wilderness."
When we get down into the history of this set its all about Wilderness folks but lets get that history outta the way shall we, "The D&D Companion Rules Set (1984), by Frank Mentzer, is the third volume in Mentzer's BECMI rules series. It was published in June 1984." This is the box set that introduced 'the War Machine system' According to the Drivethrurpg entry; "Douglas Niles and Gary Spiegel to create the game's new warfare system. He asked the two for: "a fast, easy-to-run, uncomplicated but expandable, comprehensive but not tedious, all-new state-of-the-art method for handling REALLY large battles, something that newbies could embrace but that old-schoolers could use without squawking".
The two delivered one of TSR's best received mass-combat systems, the War Machine. Niles would go on to produce a few other mass combat systems for TSR, while Spiegel would unfortunately fall victim to one of TSR's layoffs of the mid '80s."Something no one seems to take about is the fact that the Hollow World is the perfect place to test out the D&D Companion rules box set by Frank Mentzer. Its perfect for taking over large swaths of underground world of Mystara.
Its too bad because the War Machine is ideal suited to bringing the conflict, blood shed, & horror of tribal warfare to the Hollow World & the PC's can be at at center of it.
But the spell of Preservation would prevent 'XYZ' from happening.. Umm the players & dungeon master's play overrides any story element. Besides the inner world is full of undead such as the phantom, haunt, and spirit perfectly suited to give the player's PC's a run for their money. The companion set has some addition power to add into 'The Hollow World' setting such as high level dragons which could be leading that country or kingdom that the player's PC's have heard about. Finally you can actually unleash a black dragon NPC upon a Mystara campaign with some real 'heat'. Want to scare a group of players try taking on a Black Dragon within its own element with lizardmen or bullywug mercenaries.
When it comes to absolute essential information Who’s Who in the Wyrmsteeth part 2 by Francesco Defferrari from Threshold issue #9 is a must.In fact that whole issue is key if your doing anything Hollow World related.
The Companion rules complement the ritualized wars that are hinted about in the Hollow World box set & can now be carried out. Finally you get a solid set of rules to handle the dragons of Mystara & still make sense of carving out a kingdom. Somehow I've never seen the Hollow World with empires like the Sons of Azca as particularly stagnate.
And here's where the Merry Pirates come in to take full advantage of the chaos happening within the Hollow World. Their not worth the effort to take down by group of high & mighty immortals or are they? See this is where the naval rules of BECMI Dungeons & Dragons come in very handy. The higher level immortals have to come in to put things right & do a reset. Remember I mentioned those dragons? This is exactly when the PC's can expect to see tooth, claw, & breath weapons turned loose. There are always ramifications when it comes fall out from the events of a module. The real question is do the followers of entropy slip in as well?