The Engineer is a hardcore tower that attacks enemies with a rebar launcher and can build a sigular, extremely powerful sentry that requires constant maintenance. It can be purchased from the store for 4,500 and has a level requirement of Level 60. The Engineer is also available through a gamepass for 4,000.
The Engineer, unlike every other ground tower, can only be placed beside the path. This is due to the sentry, which is forced onto the path when built. The Engineer, as well as the sentry, collects scrap when damaging enemies. For the Engineer, the amount of scrap gotten per shot is equivalent to the damage dealt to an enemy. For the sentry, it gains significantly less scrap, building up about 1 scrap every 5 shots. This scrap will fill up its Scrap Meter, which has an unlimited capacity. Scrap is used to repair and upgrade the sentry, with two abilities, Upgrade and Repair serving these purposes. Whenever an ability is activated, all scrap is consumed, and both the Engineer and sentry will stop shooting until all scrap is used; the time it takes is always a set value. Upgrading the Engineer will increase the level cap of the sentry, and when enough scrap is used for upgrading (displayed via a separate meter), the sentry will upgrade.
The sentry has a unique health system, having five hitpoints at all levels. As it is placed on the path, enemy collisions will damage the sentry, damaging the sentry by two hitpoints. Every wave, the sentry will lose two hitpoints. Boss abilities will also damage the sentry by two hitpoints. When enough scrap is used for repairing, a hitpoint is restored. When all hitpoints are depleted, the sentry is destroyed and the Engineer will have to rebuild the sentry from its base level, taking 10 seconds to construct another sentry.
On all levels, the Engineer will have a Replace ability that can only be activated while the sentry is destroyed. This lets the player reposition the Engineer and maintain its upgrades.
The Engineer is considered an all-round tower due to its cheap placement cost, decent DPS on early levels and very expensive upgrades with extremely high DPS later on.
To see all the previous statistics of this tower, see the history page, while for the statistics without the Firerate Bug, visit the Firerate Bug page.
Using the Engineer is all about maintaining a delicate balance between upgrading and repairing the sentry. The sentry can and will constantly be destroyed, so your job is to keep it up for as long as possible and at a high level to output the most DPS.
For the earlier levels, it is not hard to get a sentry and keep it alive, but as the game progresses, there will be more things that threaten the sentry's destruction and scrap management becomes significantly more important. Overall, the Engineer does respectable damage in the early game, but truly shines later on, though its power scales with difficulty to use.
Positioning
How much scrap the Engineer builds up is highly dependent on its placement. The Engineer, while being the main scrap producer, has short range, requiring it be placed close to the entrance to shoot at enemies. However, this puts the sentry at greater risk of being destroyed.
The tide of the game constantly sways, so no spot will remain optimal for long. This, inevitably, will cause the sentry to get destroyed. As such, the Replace ability must be used smartly, as it allows repositioning of the Engineer and its sentry.
Once the sentry goes down, the situation should be assessed and a new spot for the Engineer should be chosen strategically. Wave structure knowledge is crucial for this, to account for strong enemies that may overwhelm the sentry.
Scrap Management
Scrap is used for both upgrading and repairing the sentry, both very important facets of the Engineer's gameplay.
Upgrading is what you want to aim for, as it boosts the sentry's DPS to great levels. This also increases the scrap the sentry generates, creating a positive feedback loop. However, due to the self damage the sentry takes per wave, as well as the danger of enemies, the sentry's health must be kept in check. There are multiple ways to approach managing scrap, but do note that the two pointers below are just two ends of a spectrum rather than being rigid:
Whenever the sentry is at a comfortable health threshold, it should be upgraded; otherwise it will be repaired. This is a safe way of keeping the sentry up, though its upgrade potential is not as great, leading to less scrap overall. This is the more consistent option with less potential for high damage.
An alternative approach is to focus mostly on upgrades, and only repairing the sentry when necessary. This makes miscaulculations much more punishing, as the sentry will constantly be closer to getting destroyed. However, the sentry will be a powerhouse, dealing much more damage as a result of being at higher levels more consistently.
As a result of the Repair and Upgrade abilities disarming the Engineer and its sentry for several seconds, spamming those abilities is very ineffective. As a result, the abilities should be used more scarcely, which leads to the sentry being significantly more tricky to manage as scrap cannot be distributed as evenly and as often, which could spell death to the sentry if it suddenly gets overwhelmed.
The longer you hold onto a growing supply of scrap, the more vulnerable the sentry will be. Do note that doing so will only allow you to use all that scrap on either upgrading or healing the sentry, not both. Holding onto scrap could end up generating lots more of it, however, as there is no downtime from repairing or upgrading. It is important to balance saving and spending scrap.
Level 6 Engineer
When the Engineer is upgraded to Level 6, multiple mechanics change.
The forced damage the sentry takes every wave is removed.
Repair and Upgrade are disabled when the sentry is at max level. Due to this, the sentry becomes unable to be healed.
As such, the best strategy is to get the sentry to full HP before upgrading it the Engineer to Level 6.
Both abilities become available again if the sentry is destroyed and rebuilt. They only go away when the sentry is at max level.
The Engineer will not be able to attack when the sentry is at maximum level, making scrap generation sluggish.
If the sentry is destroyed, the Engineer will attack again. Do note that the sentry will start from its base level when rebuilt, as usual.
A new ability, Shield, is added. Activating it brings up a shield for the sentry which blocks all forms of damage. However, the sentry will not attack with the shield up.
Replace becomes usable at any time to reposition the sentry, however at a 30-second cooldown.
The strategy here now completely shifts; all focus is directed on maintaining the sentry by blocking attacks and moving the sentry out of precarious positions, while trying to keep the sentry up as long as possible to keep its damage going. Now, sentry destruction should not be treated as the norm.
If the sentry ever gets destroyed, it will take a very long time to rebuild it up to max level, though this is made easier by the lack of forced damage and more flexible repositioning. The extremely high scrap cost to upgrade the sentry to max level is still to be taken into consideration. Generally, if a max sentry gets destroyed, it is a major loss, so like all other levels, the sentry must be constantly managed.
Trivia
The Engineer is the only tower to have three range rings.
The white ring is the Engineer's range, the yellow ring is the sentry placement range, and the red ring is a deadzone range where the Engineer cannot fire or build sentries.
The Engineer tower is very loosely based on the Engineer Monkey from the Bloons Tower Defense series.
The rebar launcher used by the Engineer is a reference to a similar weapon used by MUL-T from Risk of Rain 2.
The Engineer's sentry shield is based on the Wrangler shield, used by the Engineer from Team Fortress 2.
The store description of the Engineer is a reference to a voice line said by the Team Fortress 2Engineer, "Sentry goin' up!".
While unlikely to be seen as this can only happen through bugs, the shield sentries get at Level 4+ does not make them just immune to enemy abilities, but every form of damage, including damage from towers.
The Cryomancer can damage sentries spawned by a Level 0–3 Engineer, though at Level 4+, it will be unable to do so unless the Engineer is stunned.
The Engineer is the only tower that has 6 upgrades.
The Engineer went through multiple changes before being released.
Rather than using a rebar launcher, it wielded a pistol, which, with levels, would be replaced with various rifles.
The Engineer had five sentries instead of four, which had different purposes.
The first three sentries were single target sentries, which would only deal damage to one enemy. These sentries are still in the game, with them being the Sentry, Rifle Sentry and Minigun Sentry.
The fourth sentry was the Missile Sentry, which was a quad missile launcher that would deal splash damage.
The fifth and last sentry was the Support Beacon, which would reveal hidden enemies in its range.
Due to there being multiple types of sentries, you would be able to pick what kind of sentries the Engineer would place.
The Engineer alongside the Electroshocker are the only towers that detect flying enemies that do not gain flying detection at Level 0.
The Engineer and Sniper are the only towers that can damage any enemy, regardless of their immunities.
The Engineer Level 6 upgrade is most likely a reference to Illegal Gun Parts from Terraria.
Update History
For previous cosmetic variations, see the gallery page.
17 April 2022
Engineer added.
Level 1 upgrade name changed from Percise Calculations to Precise Calculations later the same day.
Bug: Sentry ranged damage does not increase the Total Damage counter.
Bug: Sentry collision damage does not increase the Total Damage counter.
Bug: Sentry range can be increased by the DJ Booth.
Bug: Engineer does not have lead penetration at all levels.
Bug: Sentries can be built in the deadzone range.
Bug: Engineer can collide with players.
23 April 2022
Sentries can no longer collide with enemies.
Statistical changes:
Level 4
Sentries now gain a shield which protects them from damage when it is active.
New skin: Ducky
Bugfix: Sentries can no longer be built in the deadzone range.
Bugfix: Sentry ranged damage now increases the Total Damage counter.
13 May 2022
Bugfix: Engineer can no longer collide with players.
30 May 2022
Gamepass price decreased from 4,000 to 3,000.
1 June 2022
Gamepass price increased from 3,000 to 4,000.
26 June 2022
Gamepass taken offsale.
5 August 2022
Bugfix: Sentry range can no longer be increased by the DJ Booth.
8 August 2022
Bug: Engineer sometimes does not deal damage when an enemy is hit by its projectile.
2 September 2022
Bugfix: Engineer now deals damage properly.
31 October 2022
Engineer is available through a gamepass for 4,000.
Bugfix: Engineer now has lead penetration.
11 November 2022
New skin: Mechanic
24 November 2022
Gamepass price decreased from 4,000 to 3,200.
1 December 2022
Gamepass price increased from 3,200 to 4,000.
21 December 2022
Gamepass price decreased from 4,000 to 3,000.
Firerate increased for units due to Firerate Bug getting more severe for units.
Firerate changed from 1.508 > 1.258 to 1.258 > 1.008
Damage increased from +3 to +5.
Level 4
Cost decreased from $3,500 to $3,250
Damage increased from +5 to +7.
Renamed from Pressure Tank to Improved Blueprints.
Level 5
Damage increased from +10 to +15.
Max units increased from +0 to +1.
Level 6
Cost decreased from $35,000 to $33,500
Deadzone range decreased from +0 to -1.
Max units decreased from +1 to +0.
7 April 2023
You can now see the Engineer's scrap meter when you hover your cursor over it.
Gamepass price decreased from 4,000 to 2,500.
Bug: Sentry shields are sometimes not visible.
15 April 2023
Gamepass price increased from 2,500 to 4,000.
5 May 2023
Ducky skin rarity changed from Common to Legendary.
4 July 2023
Gamepass price decreased from 4,000 to 3,000.
6 July 2023
Gamepass price increased from 3,000 to 4,000.
31 October 2023
New skin: Grave Digger
24 November 2023
Gamepass price decreased from 4,000 to 2,600.
New skin: Plushie
29 November 2023
Gamepass price increased from 2,600 to 4,000.
21 December 2023
New skin: Phantom
Notes
↑Through splash damage, hidden enemies may be hit indirectly if another detectable enemy is nearby, but units from this tower can never directly target hidden enemies.
↑Through splash damage, flying enemies may be hit indirectly if another detectable enemy is nearby, but units from this tower can never directly target flying enemies.
↑93.75 Gun DPS + 7.5 Rocket DPS. Rev-up time of 1.5 seconds is not considered into the DPS. Rocket DPS assumes only one enemy is hit and receives full splash damage.
↑Can be obtained by using a code you got for purchasing an Engineer Plush.
4,000.
