Complete overhaul of the vanilla skilltrees
There are new skilltrees for every lord and hero in the game that are designed to offer more choice in how you build your character while removing a lot of the stat-stacking and snowballing of vanilla. You can no longer buff all your unit's stats into the stratosphere or make mechanics like attrition and replenishment redundant, but on the plus side you can turn Mannfred into a wolf. Swings and roundabouts.
Skilltrees are automatically created by snooping on the vanilla skilltree to see what kind of character it is, so it should be largely compatible with any modded characters. It won't be compatible with wizard characters who use non-vanilla spell schools, but compatibility with Lore of Truthsayers, Djinn and Nagash has been included.
A note on mounts - mounts added by mods will be automatically unlocked and don't need to be bought. This is a technical limitation due to how jank mounts work under the hood.
Magic overhaul
Wizards don't pick their spells directly, but instead have a Wizard Level that determines how many spells they randomly roll each turn. Maximum WoM pool is reduced from vanilla 100 to 30, but each Wizard Level in your army will increase it by 15. Spells themselves also have some changes - all spells can miscast now and the miscast chance is based on the unmodified spell cost. Miscasts deal more damage. Some buff and debuff spells were changed to have a "remains in play" effect.
Battle overhaul
Battles are slower, with a much higher focus on causing chain routs. Morale is much higher but when a unit routs the first time they will usually shatter immediately. Be very careful when a unit starts to waver, they are likely to drag nearby units with them, especially if you have a lot of low leadership chaff clumped together.
Fatigue is slower to drain but doesn't regenerate much either. Fresh units have a heavy advantage over exhausted ones, and the advantage won't fade fast.
Changes only work in campaign, not custom battles.
Dynamic campaign movement range
Army movement range is determined by the amount and type of units in that army. An army of cavalry will move faster than infantry. Artillery is slowest.
Ammo
Ranged units will carry ammo over from battle to campaign. It replenishes at the start of the turn if you're in friendly territory (WoC and Beastmen regen a flat 40% per turn).
Devastation (aka health for settlements)
When settlements get occupied or raided their health will lower. Low settlement health means low replenishment in that region and reduced amounts of ammo replenished. Don't plan on capturing new territory and replenishing to full next turn, you might need to cycle armies out to heal them back to full.
Instability (aka health for factions)
When lords for a faction are injured or die they will make the faction unstable. More instability gives increasing penalties, such as public order and recruit speed maluses, and eventually all the garrisons for that faction will desert. This keeps wars to a few decisive battles instead of the AI endlessly pumping out new stacks followed by 57 garrison battles. Pay attention to the enemy faction leader dying, because it will cripple them for a while.
Immortality-be-gone
Any immortal character has a chance to die. Yes, including legendary lords. "But muh defeated traits", I presume someone will say. Don't worry! I removed defeated traits too! The chance for immortality to be disabled is lowered for dwarfs, and greatly lowered for undead characters. Daemons get to keep their immortality.
Dungeons
Dotted about the landscape are some dungeons to find. Only armies with 10 or less units can enter, and they'll be trapped inside until they can clear an ending. Dungeons are intended for mid-to-late game units. You can enter with your turn 1 starting army, but don't plan on leaving. You can only do each dungeon once, no farming the same one. Dungeons are only enabled in Immortal Empires (and IEE) because I'm too lazy to do all those battle catchment overrides for RoC.
Winter
The game will keep count of the current season and year, and when the winter months roll around it will get cold up north. It will make the campaign and battle maps snowy and comes with snow attrition. During the height of winter the snow will get as far south as Altdorf! Relive Mannfred's greatest moment by invading the empire during winter and then losing!
Chaos Invasion
If endgame scenarios are enabled there will always be a new Chaos Invasion enabled. All WoC and Daemon factions are removed from the game on turn 1. They will return in force when the invasion begins - first Archaon will arrive followed (over several turns) by the other WoC factions. They will take random Norscan-owned Dark Fortresses in the chaos wastes as their starting provinces and spawn with numerous high-level armies. The southern pole will also feature a mini-invasion of 4 daemonic factions. For every settlement the WoC conquer they will summon a powerful daemon army into the material realm to run amok. They will also blanket the world in chaos corruption for every settlement the forces of chaos own. Killing Archaon will force all WoC factions into war with one another, will stop new daemon armies being summoned in, and stop the corruption effect.
If you're playing as a Daemon or WoC faction and the invasion is enabled it will work much the same, but will begin on turn 1 with Archaon and chums showing up with much weaker armies. You will start in a random chaos wastes fortress and, if you're WoC, the chaos invasion rules will apply (allied to all other WoC factions, will go to war automatically if Archaon dies, yada yada).
Research
Default research rate is reduced to 10%. There are new buildings that increase research rate. Intended to give more to manage for players and slow the stat-stacking from the research tree.
Intel
You know those buildings that give undercity detection that nobody ever builds? They give a new resource called Intel, that you can use on 3 new actions. There is an action that detects undercities immediately. The AI will also use this action, at random, by looking for suspicious corruption in their territory. Keep corruption low to stop them finding your undercities and hidden cults.
Unit Upgrades
The WoC unit upgrading system is partially enabled for most other factions. It mostly just lets you swap weapon types, but for some units it can also be used to upgrade to a higher tier unit. This also sometimes comes with the removal of the higher tier unit from regular recruitment.
