In general, this mod is for people (like me) who like to do everything in a game. Visit all the dungeons, kill all the bosses, preferably get all the artifacts. By allowing all characters to visit some more restricted dungeons, we can make that a little easier. This mod is not intended to be lore-friendly, but I may make a lore-friendlier version in the future. (As it stands you can visit Irkkk as a halfling and the Yeek don't care. I may change that.)

Current mod features:
All characters can visit the Iron Throne, its shops, and its two attendant dungeons.
All characters can travel through the tunnel in the Ancient Halfling Complex to reach the Island of Rel. There they can visit Irkkk and the two dungeons.
All characters will receive caldera at level 20, and sludgenest at level 30.
The maximum level of Rel's dungeons is raised to match Halfling Complex (to 25)
The maximum material level of Rel's dungeons is raised by 1 (from 2 to 3)

Features:
Cunning/Dead Secrets - generic category available to Necromancer, Doomed and Shadowblade.
Grave Resolve: passive. Bonus to Fear immunity and Mental save.
Darktouched: active. Small resistance bonus against darkness, cold, undead. + touch attack Heals undead/harms others.
Dead Whispers: active. Grants telepathy Undead for a short time. Also let's you see what your minions see.
Necroanatomy: passive. You do increased damage to undead. Decreased damage you do to your own minions. Adds healing to Surge of Undeath. Increases max life of Doomed Shadows.

Spell/Charnel - class category available to Necromancer only.
Blood Burst: radius 1 blight damage ranged burst, splash heals undead.
Grasping Claws: mass pin/bleed.
Meat Shield: sustain, grants a physical ward on kill.
Vampiric Gift: moved from Spell/Grave

Tweaked Categories:
Spell/Grave
Chill of the Tomb: no change
Will o' the Wisps: Also buffs your cold damage and resistance a little. Grants a chance to summon a wisp on spell hitting.
Frozen Flames: Slowly burns status effects from friendly and enemies. Selective about whether it burns beneficial or detrimental.
Ghost Touch: Curse, lowers mindsave, cold resist and stun resist.

Spell/Advanced Necrotic Minions
Undead Explosion: If used on a Wisp, it will be a radius 1 freeze. If used on a Bone Giant it will provide the Bone Shield and do physical damage.
Soulwind: Increases minion's movement speed and grants a chance to recover a soul when a minion dies.
Assemble: Better level scaling.
Minion Mastery: Added a Greater Mummy that upgrades on Ghoul King. Also protects your minions from interminion damage.

Spell/Necrotic Minions
Aura Mastery move to Necrosis.
Undeath Link moved to slot 2, now does less damage to your minions, but also adds all minions life drains together.

Spell/Necrosis
Undeath Link moved to Necrotic Minions.
Impending Doom moved the slot 3.
Aura Mastery added to slot 2.

Spell/Shades
Shadow Tunnel now also includes the effect of Curse of the Meek.
Curse of the Meek removed.
Nether Breach added to slot 2. Its like Aether Breach but does darkness damage and won't hurt minions with Invoke Darkness 5.

Tweaked the talent levels granted by Blighted Summoning.

Also adds in a new class called the Spiritmancer:

The dead do not always rest easy, even free from fell influences.
Some linger, wishing to finish some unfinished business.
Others want to pass on a message to a loved one.
Some seek another chance for glory in battle or revenge against those who killed them.
They all eventually find a Spiritmancer, and bargain temporary servitude for closure.
The Spiritmancer can give form to the lost souls, allowing them to fight again. They also have powerful light and lightning magic.

Categories:
Spirit
Ghost Light: active. Summons Wisps of light. Melee light damage.
Spirit Guide. sustain. each summon you control increases your defense and saves.
Rest In Peace: active. bolt does light damage. more vs undead. becomes a beam at 5.
Spirit Form: active. can walk through walls temporarily. Light affinity.

Karma
Sprites: active. Summons Wisps of lightning. Ranged zappers.
Jolt of Fate: active. Lighting hits a random visible enemy.
Karmic Shield: active. Absorbs damage for a few turns then explodes based on damage absorbed.
Karmic Wave: active. weakish lightning damage cone. stronger when you are low on health.

Life Giver
Clay Golem: active. imbue a clay golem with the soul of a fallen warrior. Golem grants a physical resistance aura.
Poltergeist: sustain. randomly inflicts disarm or knockback against nearby enemies.
Gift of Life: active. give part of your life to your summons, healing them and making them tougher.
Hope: sustain. reduces debuff durations, increases fear resist.

Ghosts
Ghost Bulwark: active. summons a ghostly bulwark which can block attacks against adjacent allies.
Pale Veil: passive. allows your ghosts to Fade.
Ghost Berserker: active. summons a ghostly berserker. Choppy ghost.
Banshee: active. summon a banshee. Caster ghost.

Dawn
Shining Binds: active. ranged explosion for light damage and pin.
Pool of Light: active. Ground effect. Heals friendly. Lightblind enemies.
Holy Word: active. All nearby enemy undead/demons/horrors take light/arcane damage and are deafened.
Endless Light: sustain. increases light damage, light penentration and decreases spell cooldowns.

Justice
Lightning Flash: active. Throws a ball of lightning that explodes for lightning and blindness.
Peacemakers: active. Increases your summoned creatures strengths and speeds.
Indignation: active. Inscribe a symbol of justice on the ground. After a short delay it explodes with high lightning daze damage.
Righteous Fury: Lightning Mastery that also adds lightning damage to minion attacks.

Version 3.0: Compatible with ToME 1.5.0

This addon supports game play for character levels higher than 50, primarily for the infinite dungeon (I.D.). This implements a number of subtle changes, rescaling game mechanics and balance for character levels above 50 in the Maj'Eyal, Infinite, and Arena campaigns for ToME. The intent is to make it possible (though certainly not easy) to reach level 500 of the Infinite Dungeon. This is not a nerf or a buff to game difficulty per se, but, rather, an extension of the well-balanced game play from the Maj'Eyal campaign to higher levels.

Some talents and status effects have been adjusted to accommodate the higher character levels possible. You can see a summary of these by checking the "Infinite500" tab in Game Options.

Once a character enters the I.D., the level 50 cap is removed and normal stats-per-level progression is enabled from level 51 onward. The limit on how high primary stats may be trained is removed (limited by character level as normal) and dependent computed value limits are also appropriately increased. No additional Prodigies are gained automatically after level 50. (Note that additional category points and (rarely) Prodigies can be gained by completing I.D. challenges.) Talent mastery levels can be improved more than once, and talent levels are unlearnable as normal in the I.D.

NPC levels in the I.D. have been adjusted to be compatible with higher game difficulty settings.

Most monsters and bosses from the Maj'Eyal campaign are imported into the I.D. along with their respective unique drops.

Traps have been added back to the I.D.

Isolated shops can appear randomly in the I.D. There is guaranteed to be at least one shop on level 1, and they become more common for the first few levels, and then more rare with depth.

Random escorts may be randomly generated on each level in the I.D. unless a challenge has been started, until the normal number (9) have been attempted.

The lichform quest is completed in the I.D. with a new random drop instead of automatically being completed at the appropriate step. There is a new greater vault in the I.D. that affects this quest.

The Corruption/Hexes tree can be learned from a new random drop.

Most major events from the Maj'Eyal campaign are enabled in the I.D., and there is a new event that can award the cursed-aura tree.

Undead characters starting in the I.D. begin with an artefact cloak. This is similar to the Cloak of Deception, but its stats scale with character level and it can spawn randomly for other characters.

This addon incorporates some modified game mechanics:
The ability to shrug off critical hits has been changed. Instead of using the percent value to ignore crits completely, it reduces the crit multiplier by the same amount to a minimum of 100%.

Modified checkHit and checkHitOld functions are employed that allow for wider level differences between opponents (see http://forums.te4.org/viewtopic.php?f=36&t=35229).
Saving throws have been modified slightly to make them more effective at reducing the duration of status effects you fail to save against. (See http://forums.te4.org/viewtopic.php?f=36&t=36715 for details.)

Things planned for the future: scaling of world artefacts with character level, map effects with dungeon level.

CORE CODE CHANGES
Key code changes appear in:

Engine:
engine\generator\map\Static.lua
engine\interface\ActorStats.lua
engine\interface\ActorTalents.lua

TOME Module:
mod\load.lua
mod\resolvers.lua
mod\class\Actor.lua
mod\class\Game.lua
mod\class\GameState.lua
mod\class\Object.lua
mod\class\Player.lua
mod\class\interface\Combat.lua
mod\class\interface\TooltipsData.lua
mod\dialogs\LevelupDialog.lua
data\birth\worlds.lua
data\general\events\damp-cave.lua
data\general\events\drake-cave.lua
data\general\events\fearscape-portal.lua
data\general\events\naga-portal.lua
data\general\events\old-battle-field.lua
data\general\events\rat-lich.lua
data\general\objects\world-artifacts.lua
data\general\objects\world-artifacts-far-east.lua
data\damage_types.lua
data\quests\lichform.lua
data\rooms\greater_vault.lua
data\zones\infinite-dungeon\events.lua
data\zones\infinite-dungeon\npcs.lua
data\zones\infinite-dungeon\objects.lua
data\zones\infinite-dungeon\zone.lua
data\zones\ruined-dungeon\grids.lua

Other addons that affect these files might not be compatible.

A small fix to equipment/inventory and store dialogs: the first time one is opened after loading a game, it will open with all inventory types selected rather than just weapons. Later invocations will remember the tabs selected in previous invocations, as per standard game behavior.

Also available as part of the Bugnibus Bugfix Pack.

Adds a new command 'Rest for a specific number of turns', initially bound to <shift-r> (which can be rebound to your preferred key in the usual manner). A dialog will pop up for you to enter the number of turns you wish to rest.

Also available as part of the ZOmnibus Addon Pack and ZOmnibus Lite.