For me, one of the signs of a good adventure is that it makes me think about how I could expand it and/or combine it with other adventures in my collection. Legacy of the Crystal Shard is definitely one of those adventures and it continues to grow on me.
Some rather good but largely forgotten adventures were published toward the end of 2E - The Shattered Circle by Bruce Cordell being my favourite - including The Accursed Tower (link to DNDClassics.com) by R A Salvatore and friends (for an explanation of the "and friends" I suggest following the link).
The adventure is in two parts with the first part being a wilderness journey from Luskan to Ten Towns and the second part being a site-based adventure exploring a ruined castle that sunk into the earth as a result of a fiendish summoning that went awry. Both parts are easily incorporated into an expanded version of Legacy of the Crystal Shard.
The Journey to Icewind Dale
Legacy begins with the assumption that the PCs are en route to Icewind Dale but it doesn't play out that journey. The Accursed Tower contains the necessary material to alowed that 21-day journey to be played out together with, more importantly, this very useful regional map:
|Map: From Luskan to Icewind Dale|
I think Legacy could work even better with this journey incorporated as an opening adventure, particularly if the DM wants to include some NPCs that the PCs can interact with on the way who later prove important to the journey. It also allows the DM to foreshadow later post-Legacy adventures in Icewind Dale such as my plan to include a schism within the orcs from Many Arrows that will later pose a threat to the Dale. An orc ambush en route can highlight that the supposedly peaceful and civilised orcs can still pose a threat, but more on that in another post (or just read the R A Salvatore-written article History Check: Dark Arrow Keep in Dragon 429 which is the inspiration for my ideas about orc troubles).
I think my favourite part of this journey would be when the PCs are crossing The Spine of the World (encounters 10-15 on the map above). I would definitely include some sort of skill challenge involving a blizzard, an avalanche and the possibility of getting lost, plus at least one nasty encounter involving a rock-throwing giant.
And, yes, I would throw level 1 PCs against a giant in 4E... but I would modify the giant to be a solo creature with the same XP value as it normally has a standard creature. IMC, I have further modified my giants so that their level is equal to their hit dice in 1E so my hill giants, for example, are merely level 8 brutes and my frost giants are level 10 brutes. A level 10 standard creature has the same XP value as a level 1 solo creature which means a single frost giant - a hermit or renegade from his tribe - can pose just the right threat to a level 1 group of PCs.
Further, assuming I did include such a frost giant encounter, I would probably make him an exile from his tribe because he (or she) is a follower of Auril rather than the primordial Thrym. If the PCs defeat this frost giant and then cleverly think to follow his tracks back to his lair, I would probably include clues and/or items helpful to the later adventure involving the Chosen of Auril.
Of course, no journey through mountainous terrain is complete without an attack by a flock of murderous perytons or, what would be more level-appropriate, a nasty pair of same.
The Sunken Castle
One thing that Legacy, as written, is missing is a simple site-based dungeon adventure. The sunken castle from The Accursed Tower provides that and is definitely worth including even if the journey from Luskan is not.
As written, the castle is the former abode of a renegade wizard of the Arcane Brotherhood of Luskan. That backstory could still stand but I would change the encounters - and the name of the wizard - to better suit my own game. The one thing I would not change are the maps which I find to be really good and easily adapted for my own use.
It would be nice to include some sort of information-based reward here that would help with the Legacy adventure proper. Perhaps the wizard who once dwelt here researched the nature of black ice and has written a helpful treatise? Or maybe there is a quasit trapped in a summoning circle that can be bargained with to provide information about the Crystal Shard and events of the past in exchange for its freedom?
Those "interesting bits" could be in the titular fallen tower, watched over by the undead form of the former wizard. The castle itself, though, could now be the demesne of a band of kobolds or goblins or, with a bit of imagination, something more interesting but still appropriate for low level adventurers.
What I do think is important though is having the option of a simple site-based adventure to round out Legacy. I think this second part of The Accursed Tower provides such an option.