Monkey vs. Monkey

 (or MvM), is a feature in Bloons Monkey City that allows players to attack other players with bloons assaults which players will have to defend their city from. The attacker will receive City Cash, XP, and Honor for successful raids, but they will lose honor for lost attacks. Players can choose not to participate by not attacking any player for 72 consecutive hours; this is called "pacifist mode". This will prevent any attacks from coming to the player. However, players who have over 1000 honor or attack someone during Pacifist Mode will be susceptible to attacks. (the latter will break out and have to wait for 72 more hours again or lose his/her honor to make it below 1000).

Attacking Players
To participate in Monkey vs Monkey, the player's city is required to be at least level 9. Also, the player needs several buildings to raid and defend against other players: When attacking a random player (a Quick Match) or a friend (Attack Friend feature), the player will have the option to choose the highest bloon type and amount of Bloontonium spent. Attackers with higher city levels will require having higher-ranked bloon types to attack. Also, the player will be given the option to send extra regrowth, camo, lead, and MOAB-Class Bloons for the price of 10 for each extra option chosen, and 15 for regrowth. The more Bloontonium the player sends, the more Bloons will be generated (1 for every bloon spawned). At the highest levels, the highest and lowest ranks will range from all MOAB-Class Bloons. However, the rounds will be computer-generated, and the defense rules for the other player will apply.
 * Bloon Inflation and Deployment Facility: This is required to send an attack against other players. In BMCM, This structure has a different look, takes 2x2 tile, generates and stores its own Bloontonium, and players can only launch attacks when their Bloontonium supply is at 100%.
 * Bloontonium Storage Tank (Flash Only): This building is necessary for the player to store Bloontonium, which can then be used to assault other players.
 * Bloontonium Generator (Flash Only): This facility generates Bloontonium at the rate of a Banana Farm building. It is one of many ways to generate Bloontonium; the player also can fill their tanks by defending other players' raids, capturing Treasure Chests, capturing MOABs Graveyard tiles, or using Bloonstones. (As a bonus, their tanks will be filled up on their first attack........
 * Bloon Research Lab: This laboratory is required to research and send bloon types stronger than green bloons.

Defending an Attack
When a player gets an attack, it's placed on the lowest XP tile they have (random on mobile), so they always appear closest to the 3x3 section of city where they started. The player has to defend the tile in apopalypse-style; if they lose, money and honor is stolen from their city and if the player doesn't have enough cash for it, random buildings are temporarily disabled (always one is disabled on mobile even if the player has the money) which can often be frustrating. Also, there is a 24-hour time limit which starts after a player logs in after an attack is sent. If the time limit expires before the player defends their city against the attack, then they automatically lose just as they would if they lost all their lives, but in the battle history, the track picture is replaced by a 'Attack Expired' picture on a stopwatch with a monkey pointing to it. If this occurs, defenders won't get salvaged bloontonium because they didn't defend their city in the first place.

Differences between Flash and Mobile
Mobile:
 * Exclusive in-game music is absent (uses tile music)
 * No bloonstone cost to retry defense upon loss
 * Can pause in-game
 * Attacked tiles are random
 * Tiles are not captured regardless of battle outcome, no bloonstones or city cash is given for beating the attack either (just honor and bloontonium).
 * Bloon Inflation Factory takes 2x2 tiles; generates and stores Bloontonium, replacing storage tanks and generators; can only attack when 100% full
 * A Building is required for each: Fast Bloons, Thermal Bloons and Rainbow Bloons.
 * No DDTs
 * Money stolen is based on player's level, and is greatly reduced (to 75 x PlayerLevel). However, this is replaced with a building always being destroyed, even if the player has enough money.
 * Honor award amounts are fixed. Losses are -2 honor for losing, regardless of city level, difficulty of attack, or your opponent's honor (succeeding defended attack is always +10, succeeding an outgoing attack is +15, defending attack on first try is +2 honor, second and beyond is +5 honor and some cash).
 * Attack Types/strategies and are used instead of Assaults, however some have an option to send extra strong attacks (for the price of 10).

Flash:
 * Honor gained/lost is based on opponent's honor, and that amount is higher than that on mobile. (30 honor on average, both for losing and gaining, and only 1 honor is gained between both players)
 * Variable Difficulties for attacks, minimum bloontonium amount is 250*OpponentLevel - 1000, and can range from Medium to Hard (below level 12), Very Hard (levels 12-32), Impoppable (level 33 and up).
 * Money stolen is based on the level of monkey banks.
 * For level 1, it's 50% of its capacity (750).
 * For level 2, it's 40% of its capacity (1800).
 * For level 3, it's 33% of its capacity (2970).
 * For level 4, it's 25% of its capacity (3750).
 * For level 5, it's 20% of its capacity (5000).
 * Anything above level 5 has not yet been confirmed.
 * Buildings only get damaged if you don't have enough city cash.
 * Bloontonium Generators, Bloontonium Storage Tanks, and Bloon Inflation and Deployment Facilities are three different buildings that only need a single tile for each.