Bloons Wiki
Bloons Wiki
For a quick overview which path to go for with each upgrade, see Crosspath Chart.

Crosspathing is a term used to describe which upgrades have been purchased along two separate upgrade paths.

In Bloons TD 5, each tower has 2 upgrade paths with 4 levels or "tiers" of upgrades. Upgrades can be bought for both the left and right path, but upgrades for tier-3 and above can not be purchased for both paths. This effectively forces the player to choose which path to fully upgrade, and which path to leave as the minor crosspath. Crosspathing plays a much more strategic role in Bloons TD 6, where there are three upgrade paths, only 2 of which are selectable per tower. The limitation of not going past tier 2 for both still remains.

For the sake of displaying a complete list of crosspathing choices and their uses, this page will display all possible crosspathing choices and indiscriminately show each and every one of them.

Crosspath Notation: What do these Numbers Mean?[]


Upgrade Menu of a Dart Monkey with Spike-o-Pult and Enhanced Eyesight. Spike-o-Pult is a tier-3 upgrade while Enhanced Eyesight is tier-2. This locks out the middle path leaving the crosspath notation to be 3-0-2.

Across discussions of Bloons Tower Defense readers will frequently encounter numbers written like 4/2 or 5-2-0. These numbers are the Crosspath Coordinates or Crosspath Notation of a tower's upgrades. They represent the number of upgrade tiers purchased for each of the tower's 2 paths in BTD5 and 3 paths in BTD6.

In Bloons TD 5, each tower has 2 upgrade paths with 4 levels or "tiers" of upgrades that are bought one after the other. The upgrade notation here is Left Path-Right Path. Upgrades can be bought independently for both the left and right path, but upgrades for tier-3 and above can not be purchased for both paths. So, to represent a tower with 2 upgrades bought on the left path, and 3 upgrades on the right, the notation 2/3 or 2-3 would be used. An example of a 2-3 tower would be the Mortar Tower with Bigger Blast and Signal Flare. Note that a 3-3 tower can not exist due to the tier-3 limit on the second path. 0 is used to represent no upgrades being purchased on that path.

Similarly, in Bloons TD 6, there are three upgrade paths, only 2 of which are selectable per tower. And only one of these paths may be upgraded to tier-3 and above. The upgrade notation here is Top-Middle-Bottom. So to represent a tower like the Heli Pilot with the Apache Prime and Bigger Jets upgrade, 5-1-0 would be used. This is because the Apache Prime is the 5th tier upgrade for path 1, giving the 5 in the left most spot, and Bigger Jets is the 1st tier upgrade for path 2, giving the 1 in the middle spot. The zero represents no upgrades being bought on path 3. It would be impossible to have a notation such as 3-0-3 as this violates the rule of not having more than one path go past tier-3. Likewise, 4-1-1 is a rule breaker because three upgrade paths were selected. One of the three numbers will always be 0.*

Additional Notes and Caveats:

  • A zero is used to represent no upgrades being purchased on that respective path
    • A 0-0-0 tower is a tower without any upgrades. These are also called "Base Towers".
  • An "x" is used whenever the number of upgrades on that path are not relevant to the discussion. (i.e. "Purchase a x-x-4 Monkey Village to enhance income generation.")
    • An "X" in specifc places means that the player upgraded a tower in specifc paths, but the tier of those paths don't matter. (i.e. "A 0-3-X Tack Shooter shoots every 1.19 seconds" or "A X-X-0 Dart Monkey has no innate Camo Detection")
  • Players will frequently encounter Crosspath coordinates that seemingly break the rules like 5-5-5, or 2-3-2. These denote the maximum tier of upgrade available on each path, rather than an actual 5-5-5 tower.
  • However, there are rare examples of true 4-4, and 5-5-5 towers known as Crosspath Hybrids which break these rules. These include the Wizard Lord, VTSG, Paragons and to a lesser extent, Archmage.
    • Paragons were formerly 6-0-0 towers.
  • You may have also seen notation such as 1/1/1/0 and 2/2/2/1 in the context of the Sun Temple and True Sun God. In this case, the numbers refer to how many times each category of tower has been sacrificed and the numbers in the parenthesis specify the price tier level of each sacrfice with tier 9 being the highest tier of sacrifices. The notation here is Primary(#,#)/Military(#,#)/Magic(#,#)/Support(#,#). So a 1(9)/1(9)/1(9)/0(0) Sun Temple has level 9 Primary, Military and Magic sacrifices with no Support Sacrifces. A 2(1,1)/1(0,9)/0/0 True Sun God would have 2 instances (with both instances being the lowest tier above 0) of Primary and 1 instance of maxed Military sacrifices.


Within the Bloons Wiki, the use of "crosspathing" refers to how mixing upgrades work to how towers function in a defense. The sheer number of crosspaths in Bloons TD 6 means that there will be questions about possible confusion over the expanded upgrade system compared to that from Bloons TD 5.

Q1) What is a crosspath?

In Bloons TD 6 Generation games, a "Crosspath" refers to to choosing 2 out of the 3 paths to upgrade your monkeys.

The entire crosspaths system is a system design to make towers more versatile or more speicalized to various degrees. Because not all crosspaths will benefit tower the way that it needs to operate at it's best, there will be crosspaths that are better than others. Identifying what crosspaths are best suited for each path for any given situation is the main part of strategy in Bloons TD 6.

Making sure that each path has a crosspath works well with another path is key with Crosspathing. This will allow the player to be efficient with their upgrade purchases and make harder challenges easier to complete.

Q2) Why does crosspathing mostly refer to BTD6 upgrades?

Since the player cannot access all paths of any monkey (Once they choose upgrades from two different paths, the path that the player didn't choose will instantly be locked out.) in Bloons TD 6 due to the fact that three paths exist means that the tower will miss out on all of the benefits of that path. Towers in BTD5 that had upgrades in the same path but are now in separate paths (Ninja Monkey and Boomerang Monkey for example) in BTD6 are especially affected by this as they cannot get all of the benefits of those three upgrades.

Also in BTD5, crosspathing isn't as impactful as all towers have access to 6 out of the 8 of their upgrades (unlike in BTD6 where every tower has access to 7 out of 15 of their upgrades) and due to that fact that the player can choose all paths to upgrade, which means they don't entirely miss out on the benefits of the high tiers.

Q3) How can a tower be "unaffected" by crosspaths?

It is not that they are truly unaffected by crosspaths (since those crosspaths can improve the tower), it is that the main strength of that doesn't come from its main attack which is usually the most affected by crosspaths. These towers typically have an ability that mostly won't change in any way even if crosspathed because its a temporary new attack. Towers that fill the support role are another example of tower that are "unaffected by crosspaths" since the buffs themselves aren't affected by crosspaths. However, there are exceptions to this. Usually the buffs range of affect is directly dependent of that towers range. This means that crosspaths that increase the range of that tower can most of the time, increase the number of towers that are affected by the buff, which can make a significant difference in a defense. Monkey Village is a good example of this. Unlike most support towers, Monkey Village crosspaths can directly affect the buffs it gives to the same degree as DPS towers.

Q4) Why can't I just look at a page for a specific upgrade to know what the best crosspath is?

Unfortunately, not all pages provide what all crosspaths is the most efficient and it's better to look at this page, especially if you want to know the strength and weakness of multiple crosspaths at once since you don't have to wait for a page to load each time the you want to know.

Q5) Why don't you just show what crosspaths are good or bad for each upgrade? I can't seem to find the right information easily.

We show all crosspaths due to these two reasons:

  • Reason 1: Due to the sheer number of crosspaths that can be done in Bloons TD 6, it's possible for one player alone to choose an inefficient upgrade because they don't know how that crosspath negatively affects the tower they are using. To alleviate the question of which is the better crosspath for a specific upgrade, we show both the good and the bad crosspath so it is possible to know why a crosspath is preferred over the other and why you should avoid a specific crosspath.
  • Reason 2: Custom challenges can be made to highlight a specific crosspath that is considered "bad" or "inefficient" and proving that it can work. A common instance being those "Find the Underrated Crosspath" challenges as these forces the player to think what upgrades and crosspaths are considered "bad" and "not efficient" since most of the time, the player would want the best crosspath for each upgrade. A pretty famous example among ISAB fans is the 0-3-2 Super Monkey, more commonly referred to as the ISAB Monkey, as it has been used to complete very specific challenges.

This page can help both Challenge creators and challengers alike since the challenge creator can restrict upgrades so that the challengers are forced to use a specific crosspath that they are unfamiliar with, or that it is generally agreed upon the community as "bad" or "inefficient" and proving that it is possible to make it work and it helps the challengers who are looking for solution on crosspaths the challenge creators forgot to take into account.

Outside of challenges, the main structure of this page and its subpages is to list all the "good" and "bad" crosspaths and how they will be useful in their respective roles. While some may seem obvious as to what specific crosspaths are so-called useful, others may not be at all obvious or are often misused due to confusion. Focus for each tower is going to be the core to describing every single crosspath. In particular, all of a tower's crosspaths will be described and each subpage for each tower will show how to optimize towers as a whole by utilizing particular crosspaths to their advantages and avoid the less useful crosspaths.

All crosspaths must be listed, whether or not it's very obvious as to what is "good" or "bad". There are some cases where a very specific crosspath would make a significant difference on gameplay. This is especially so on CHIMPS, where it is not possible to undo crosspathing mistakes made by the player due to selling not being enabled and since the player can only work with the money the game gives the player (barring Monkey Business/Commerce).

Q6) I think Crosspathing has a much bigger impact on X (Insert tower name) or I think you are underestimating the impact of Crosspathing on Y (Insert tower name).

While it is true that the player cannot quantify the amount of impact crosspathing has on a tower, there are pretty clear differences to an upgrades power when different crosspaths are enabled. In order to accurately tell whether a tower is heavily impacted by crosspaths or not, the player must ask these questions:

  • Does the main power of that towers higher tier (Tier 3+) upgrades come from its main attacks? (i.e. Sniper Monkey's Large Calibre, Shrapnel, or Even Faster Firing) or does it come from a separate attack that isn't its main attack (i.e. Engineer Monkey's Sentries, Cleansing Foam/Ultraboost, or Bloons Trap). If so, does the lower tier upgrades (Tier 1 and 2) affect the main attack or that separate attack. If the lower tier affects the opposite of where its main power comes from (i.e. A tower whose main power comes from a separate attack and most lower tier upgrades affect the main attack, then that tower isn't really affected by crosspaths.) This is usually the main factor into whether or not a tower is affected by crosspaths.
  • Are there any special crosspaths interactions for specific upgrades? (i.e. Crossbow Master's arrows gain 16 pierce with 1-0-5 and 23 pierce with 2-0-5. Where as a 1-0-0 and a 2-0-0 dart monkey gain only 1 pierce and 2 pierce respectively) If so, how many crosspaths have these integrations (i.e. Glaive Lord, Perma Charge and MOAB press having special crosspath interactions.)

The impact of Crosspaths can be gauged like a spectrum and towers are not stuck to just a simple, "Super Monkey is/isn't affected by crosspaths." Some towers are impacted by crosspaths to various degrees and it is important to know what towers are really are affected by crosspaths so that the player can be more careful in upgrading certain towers in their defense.

The page for Crosspath Chart will give shorter and more succinct information regarding crosspathing, mostly for the higher tiers. It mostly shows what you get for each path and and extra information for special crosspath interactions.


Primary Monkeys[]

Military Monkeys[]

Magic Monkeys[]

Support Monkeys[]


Base Tier Crosspathing[]

Tier 1 Crosspathing[]

Tier 2 Crosspathing[]

Tier 3 Crosspathing[]

Tier 4 Crosspathing[]

Tier 5 Crosspathing[]