Your general order should be
- Fixes. Many mods create new resources from the existing ones, so getting in the fixes early prevents errors in the original files from propagating to mod files.
- Atypical Content Mods. This category is a little hard to describe. There are some mods that don't really interact much with other mods (e.g. Ace's Alternate Soundtrack) or which are designed to only alter original game files (e.g. Improved BAMs) without worrying about modded content. Because of how WeiDU (the modding tool that actually installs the mods) handles and preserves installation order, the earlier you can place mods like this the easier it will make any future mod updates to your installation. This is also a pretty good place for item/store mods, especially if they're stable and unlikely to be updated often.
- Quests/Other Content. Once you've got a solid base, it's time to start adding actual content.
- NPCs. NPCs should go after quests simply because some NPCs will detect modded quest content and provide interaction with it. You may find a mod NPC commenting on a mod quest, but only if the NPC follows the quest in the installation order.
- Tweak mods/tactical mods. Most in this category are written to be universal, i.e. they'll freely change items/creatures/scripts/etc. from other mods, but they can only do so if those resources are present when they're installed. This is why just about every tweak mod suggests it goes last in the install order.
There are, of course, all sorts of exceptions, or mods that really don't fall cleanly into a category. The readmes are there for a reason, and most modders try to help players avoid issues with install recommendations and compatibility concerns. A lot also depends on how the mod is written--Ascension, for example, used to be recommended very early in BG2 install orders due to the ancient way it had been written. Now that it's been modernized it can be installed in a more natural place in the order. With that in mind, here's a rundown of a good IWD mod order using some of the more common mods. (If there's something missing, I'll do my best to add it to the order.) In the interest of full disclosure, I am the author of IWD Fixpack, IWD Tweak Pack, Unfinished Business and Item Upgrade.
First, get your game in order:
- If you don't have the Heart of Winter expansion, install Icewind Dale and add the official IWD-only patch, which brings your game up to v1.06.
- If you have Heart of Winter, install Icewind Dale and Heart of Winter (no need for the IWD-only patch). Now you have two choices: one is to install the Heart of Winter patch, bringing your game up to v1.41. But why do that when you could...
- Install the free expansion Trials of the Luremaster, which includes the bug fixes from the official HoW patch alongside a whole mess of new content, bringing your game up to v1.42.
- If you have purchased your game from GOG it already includes Heart of Winter with the Trials of the Luremaster expansion (v1.42). You can choose not to install Trials of the Luremaster, which is the equivalent of a patched Heart of Winter install (v1.41). With or without Trials there's no need to apply one of the official patches.
Auril's Bane (aka AB): The whole reason I put in the long aside about Ascension above was to lead up to Auril's Bane. Auril's Bane makes some sweeping changes to the game with a slew of new items, spells, content, fixes and more. As of its current version AB more or less overwrites everything it touches, meaning it would wipe out many changes of mods installed before it. I would strongly recommend eschewing Grog's IWD Fixes component in favor of the IWD Fixpack. The core component also has its own version of the Voice of Durdel Anatha, making it incompatible with the same component from Unfinished Business.
One Pixel Productions Animation Fixes for IWD:TotLM: Contains some animation fixes for Icewind Dale. The Restore combat stance animations component misbehaves a little in that it not only overwrites some scripts, but the scripts include some minor syntax errors. This is the reason why this is listed before...
The IWD Fixpack: Fixes are good, and lots of fixes are better. The only reason it's not first is because the mods before it are currently a little overwrite-y. If you use this you do not need Grog's IWD Fixes from AB or...
Redrake's IWD Fixpack: I'd recommend the more extensive and modern IWD Fixpack instead, but if you're going to use this, it should go here in the order.
One Pixel Productions High-Quality Music: Replaces the default music with the same, but higher quality, soundtrack ripped from the music CDs. This can probably be installed anywhere in the order, but since it's unlikely to change it should go earlier in the order.
Improved BAMs: Improved BAMs seeks to differentiate the appearance of items in IWD, many of which use the same graphics. (A BAM is a type of graphical file used in the IWD engine.) Both IWD Tweaks and One Pixel Productions have similar components--while not really incompatible with one another, generally the last one installed of the three will take effect so you'd be best served by simply picking one and eschewing the other two. (Note that 1pp and Tweaks both have other components, so even if you use Improved BAMs you may want to install those for other components.)
Item Upgrade for IWD: A small content mod that allows players to upgrade a handful of items with no known incompatibilities. Putting it here allows for later mods to alter the new items.
Unfinished Business for Icewind Dale (aka IWD UB): A mod that seeks to restore quests and other content that was either cut or left partially completed in the game. As noted above Auril's Bane provides its own version of the Voice of Durdel Anatha quest, so UB's version won't install if it detects AB.
Icewind Dale NPCs (aka IWD NPCs): A mod that provides five new NPCs, complete with banter. IWD NPCs requires the Heart of Winter expansion, but otherwise should be compatible with other mods on this list.
Full Plate & Packing Steel: This mod implements a thorough rework of how armor works in the game. It has its own take on casting and thieving in armor, and is therefore incompatible with the Thieving in Heavy Armor and Allow Arcane Casting in Armor components from IWD Tweaks.
One Pixel Productions (aka 1pp): A high-quality and thorough remake of many graphical aspects of IWD. This should be installed late in the order as it has a lot of tweakish content changes to make its graphical goodness possible. As noted above with Improved BAMs, the last version of item icons generally wins.
Icewind Dale Tweak Pack (aka Tweaks): A collection of 30+ rule changes, cosmetic tweaks, cheats, and more, each available individually as separate components. Install Tweaks as late as possible so it can affect all modded content before it. Icon Improvements will take precedence over previous, similar components from One Pixel Productions and Improved BAMs. The components to allow thieving in heavy armor and to allow arcane casting in armor are incompatible with Full Plate and Packing Steel.
The Widescreen Mod: Allows players to play the game on modern, high-resolution monitors. Despite its name, it can be used on any aspect ratio monitor to increase resolution.
There are, of course, several thousand ways you can combine the mods above and no one can predict the outcomes of them all--and that's assuming the mods themselves are bugfree in their current and future incarnations.
I'll be happy to answer questions or take any other feedback below.