The Underhollow is a dungeon brawl in which eight teams of three players must battle and evade each other on a maze-like map in search of Roshefort, Roshan's rarest cheese. This game mode is only available to owners of The International 2018 Battle Pass.
- Be the last team standing to win.
- Dead allies can be revived to 50% HP/MP by clicking on their gravestone and waiting a few seconds.
- If an enemy dies, but their team remains alive, you can eliminate the enemy completely by clicking on their gravestone. This takes 20 seconds.
- A team is defeated when all its members are dead.
- Eliminate other players to acquire their gold and items.
- You can prevent this by moving your items to stash while you are dead.
- An "Eye of Roshan" appears regularly on the map:
- Players can pick from most of the heroes available in Dota. Their abilities remain unchanged from the base game of Dota.
- Heroes start at Level 1, and have an , , and two s.
- Clearing a room of enemy NPCs spawns a treasure chest at the center of the room, which drops gold bags, random items based on the room's tier, and health and mana potions.
- Clearing a room also rewards each player in the room with gold and experience.
- The amount of experience and gold gained differs based on the encounter type (creature encounters and chest encounters), and are scaled by 0.5 for each encounter level, starting at x1 for encounter level 1 to up to x2.5 for encounter level 4.
- Base gold per player for a creature encounter is 75. Base gold for per player for a chest encounter is 100.
- Base experience per player for a creature encounter is 300. Base experience per player for a chest encounter is 200.
- Shops have a 50% chance to appear in rooms. They sell items and healing potions.
- Rooms closer to the center are more difficult and contain better loot.
- Rooms range from level 1 to level 4. Certain encounters can only be found in certain room levels. A table of these encounters is below.
- Each depth level (cavern ring segment) contains a decreasing amount of trap rooms (higher depth means deeper towards the center of the cavern):
- Depth 1 has 4 traps
- Depth 2 has 2 traps
- Depth 3 has 1 trap
- Depth 4 has 0 traps
- Roshan destroys a ring of rooms every five minutes, starting with the easier outer ring. Players in destroyed rooms take very high damage per second.
- The contents of the map are randomly generated each time you play, so while the rooms physically remain the same, their location, difficulty and rewards will differ.
- By default, every room will always have between 5 and 7 breakables and between 5 and 7 trees positioned randomly around the room. Unless it is a special room or if a particular encounter spawns additional trees and/or breakables.
||The 15 invisible until players are within 300 range. They apply on hit.s are||2|
||The 8 Mini-Mages haveand . They also use on the closest player with less than 5 mana.||1|
||The 2 Eimermole Taskmasters castand . They are accompanied by 9 Eimermole Workers that melee nearby players.||1|
||The 2 Ogre Smashers caston any player in melee range on cooldown, and otherwise.||4|
||The 2 Pangoballers cast, upon players entering the room. Despite never leaving , they can be stunned or disabled to make it easier to hit them. They are accompanied by 8 s that melee nearby players.||3|
||The 8 stationary Deformed Wizards hurl fireballs towards where players are standing. Fireballs hit the first player unit that they come into contact with. Can be avoided by moving out of the way.||2|
||The 16s cast a modified that bashes for 0.75 seconds on the nearest player.||1|
||The room contains two Large Splitters. Upon death, these split into a few Medium Splitters, then they split into a few Small Splitters. This room deals progressively more damage as the creeps split.||3|
||The Troll Camp is inert by itself. When attacked, it spawns Trolls. If players ignore the camp, they are able to bypass it completely, but will not gain any loot. Unlike most other units in Underhollow, these troll creeps do not grant experience when killed.||1|
||The 2 Netherdrakes caston cooldown at random players, which covers the ground in acid and deals high damage over time. They are accompanied by 10 Viperlings, that attack nearby players.||1|
||The 4 Knights of Ostarion can only be truly killed when all of the knights in the room are using, which takes 4.5 seconds.||3|
||The 15 Zombies melee nearby players, and do not respect room boundaries.||1|
||The Elder Fae (Dark Willow model), periodically attacks players and casts a few of's spells. She periodically casts on nearby players. This boss is accompanied by 6 s that melee nearby players.||2|
||The Void frequently channelson nearby players. This boss is accompanied by 9 s that melee nearby players.||3|
||The Crazed Sniper attacks the closest enemy target in range, knocking them back 35 units. He has ain his inventory, which he uses after he reaches 33% HP.||2|
||Casts an amplified. Transforms with and uses when below 50% HP.||4|
||The Lord of Oblivion casts a few of's abilies. Every eight seconds, he rotates between casting in an arc in front of him while using on cooldown, and using on the closest player. Does not move.||4|
||The Protector of the Red Mountain rotates through's active abilities, including , an Aghanim's Scepter-enhanced , and . The Protector also targets invisible heroes with it's Enchant Totem and Fissure abilities, even if he cannot actually attack them normally.||4|
||A small, it infests crates and wait for players to break the crate. Once revealed, it chases players and casts and . It possesses . It does not respect room boundaries.||1-4|
||The blades swing around the room. They instantly kill any player who walk into their path.||1-4|
||Four invulnerables surround a treasure chest. They periodically cast a slow-moving at players in the room.||2-4|
||A room scattered with 25-65(depending on room level). These function the same as Techies' Proximity Mines do, making a noise when the player is in range, and exploding a moment afterwards.||1-4|
||Four invulnerables surround a treasure chest. They periodically cast at players in the room.||1-4|
||Thein this room is untargetable. A is eternally bouncing around the totems in the room, and can bounce to players.||1-4|
|Statue of Gondar||
||Reveals all enemy players on the map.||1-4|
|Statue of Karroch||
||Randomly spawns a friendly Hawk or Boar companion for the team that activates the statue.||1-4|
||A room consisting of a 10x7 grid ofs.||1-4|
||A treasure chest is found in the room.||1-4|
||Attack the chickens to make them drop gold.||1-4|
||Many destructible crates are found in the room.||1-3|
||A shopkeeper is found in the room.||1-4|
||Juggernaut has 2 phases. Once he reaches 50% of his health, he switches to phase 2 where he shrinks to 0.6x of his model scale (down from x2 of his model scale) and increases his move speed by 100 (from 250 to 350). He also uses hisability in this phase, if it is off cooldown. 4 Juggernauts spawn in this room encounter.||2|
- Various types of treasure chests can be found by clearing rooms.
|Standard Chest||Contains random items, gold, and cheeses.|
|Trap Chest||Contains a trap. More info needed.|
|Chicken Chest||Contains chickens. Hit the chickens as they run around to make them drop gold.|
|Level 1 Treasure||Level 2 Treasure||Level 3 Treasure||Level 4 Treasure||Level 5 Treasure||Level 6 Treasure|
Items and gold
- Items are found in chests, crates or purchased from shopkeepers.
|Gives 25 Battle Points and 150 gold.|
|Gives 180 Battle Points and 900 gold.|
|Gives 330 Battle Points and 1200 gold.|
|Roshefort Cheese||Gives 300 Battle Points. Spawns randomly in a chest. All players are notified when it spawns, and when it's picked up.|
|Experience Tome||Gives 125 XP.|
|Gold Bag||Gives 5 to 125 gold. Bags dropped by players give gold based on how much they carried on death, plus a sum of the sell value of their items, excluding their 3 most expensive items.|
Picking up gold bags dispels temporary invisibility (Escape Potions, , etc.)
|Health Potion||Restores 40% of a player's maximum health.|
|Mana Potion||Restores 25% of a player's maximum mana.|
|Escape Potion||Grants 15 seconds of invisibility and 30% bonus movement speed.|
Attacking, casting a spell, picking up a gold bag, or attempting resurrection will break the effect.
Creates a 300 AOE gray smoke cloud upon use. Can be sold during setup time for 200 gold (or half of that, if hero is picked earlier that the last 9 seconds of picking phase). Stacks in the inventory.
|Stick o' Dynamite||Detonates after 4 seconds, dealing 1000 physical damage in a 500 radius.|
Can be used to remove destructible walls and rock walls.
Can be bought for 750 gold in the shop and sold at half of that. Stacks in the inventory.
The following items cannot be purchased, built or found in this game mode:
All items are fully sharable with allies. Besides this, the following items have been further modified:
- Dynamite can be used to destroy the otherwise impassable stone walls, or sold for 800g, or used as a 1000-damage nuke against enemies. Be careful though, as the explosion will damage everyone in the radius, including your team.
- Always open chests before going shopping. Often, whole assembled items will drop from chests, which may change your purchasing choices. Alternatively, you can sell the items you receive from those chests for gold.
- s can be placed on the other side of gates and stone walls to scout ahead, or left behind to detect flanking enemy teams.
- Some heroes are better at clearing creeps, some are better at clearing "boss" units, and some are better at fighting enemy heroes. Try to find a good balance between these so that your team is not too weak in one area.
- s restore a lot of health early on, and is not canceled by non-player damage.
- Some of the map is on higher elevation than others, giving a vision advantage. Always try and fight enemy ranged heroes while you have the high ground.
- Escape Potions are extremely useful for re-positioning, scouting, and initiating.
- Channeling resurrection while invisible will reveal you to nearby enemies.
- Beware invisible enemy players as the game progresses, especially heroes like , and in the very late game with 2-3 teams remaining when becomes more common. Buy detection to prevent enemies from getting the drop on you.
- Some rooms may be too difficult for your team. There is no shame in trying to run through the room to avoid the fight or looking for another way around.
- Remember to rest and shop between rooms in case you run into an enemy team in the next room.
- Many, if not all, sounds in this mode can be heard through the fog. It is possible to identify where enemies are by where you hear sounds coming from, long before you actually see them.
- Stick with your team. There is very little reason to ever split up.
- Divvy up room loot fairly to whoever can use it best. Avoid selling loot until everyone already has full slots. Remember, don't be greedy -- you win as a team, and you lose as a team.
- Items are shareable. Pass your to Gyrocopter after using your upgraded ability. If you're about to die, pass your best items to a core teammate to push through a fight.
- Players can earn Battle Points for The International 2018 Battle Pass.
|Find a standard treasure||20 Battle Points|
|Find a Small Cheese||25 Battle Points|
|Kill an enemy player||30 Battle Points|
|Find a Big Cheese||300 Battle Points|
|Win a match||750 Battle Points|
Caps and bonuses
- Players can only earn a maximum amount of Battle Pass points per week. This cap can be increased by leveling the Battle Pass.
|Battle Pass Level||Points Cap||Points Multiplier|
- Emoticons are rewarded for winning matches.
|Win The Underhollow 1 time|
|Win The Underhollow 5 times|
|Win The Underhollow 10 times|
- The Underhollow is a battle royale with cheese, referencing the famous Royale with cheese scene from Pulp Fiction.
- The room Knights of Ostarion room's description text is in all caps. This is a reference to CAPS LOCK LEORIC, an infamous item build from the DotA Allstars days.
- The Golden Nether Lord's Regalia Set. This set was distributed to only 25 players worldwide, making it one of the rarest cosmetics in the game. model in the "Lord of Oblivion" room is wearing the
- The room "Exort Trionis!" contains small s casting . When Sun Strike is d by players, Invoker will often say the phrase "Exort Trionis!", meaning "Three Exort", the invoke code for Sun Strike.
- This game mode shares assets with The Emerald Abyss terrain.
- The Ogre Smasher room was originally intended to have that would cast and throw at players, but were cut prior to release.