Level 1 | Level 2 | Level 3 --- | --- | --- ![Sentry Gun Level 1](http://classicfortress.net/images/sentry-gun-level-1.png "Sentry Gun Level 1") | ![Sentry Gun Level 2](http://classicfortress.net/images/sentry-gun-level-2.png "Sentry Gun Level 2") | ![Sentry Gun Level 3](http://classicfortress.net/images/sentry-gun-level-3.png "Sentry Gun Level 3") > The Sentry Gun's appearance at different levels. The Sentry Gun is the [Engineer](Engineer)'s primary way of dealing damage. It can be built anywhere on the map (as long as it can stand on something) and costs 130 [cells](Cells) to build. The Sentry Gun is initially level 1 (seen to the far left above), but can be upgraded up to level 3. Upgrading your Sentry Gun to level 2 increases damage by 2x and makes it a bit sturdier. Level 3 adds [rockets](Rockets) and more [health](Health). See below. Level | Health | Shells | Rockets --- | --- | --- | --- 1 | 150 | 100 | 2 | 180 | 120 | 3 | 216 | 144 | 20 ## Restocking the Sentry Gun Restocking the Sentry Gun is as simple as hitting it with your [Spanner](Spanner). If you have resources ([shells](Shells) and [rockets](Rockets)), the Sentry Gun will be restocked at a rate of 40 [shells](Shells) + 20 [rockets](Rockets) per hit. See table above for maximum ammo capacity. ## Upgrading the Sentry Gun To upgrade the Sentry Gun, hit it with your [Spanner](Spanner). Upgrading costs 130 [cells](Cells). ## Rotating the Sentry Gun To rotate the Sentry Gun you need to continually hit it with your [Spanner](Spanner) until either the Sentry Gun is fully loaded or you run out of resources. A menu will then be brought up where you can rotate the Sentry Gun 45 degrees to the right/left, or turn it 180 degrees.