Horde Defenders Sentry upgrades: damage, fire rate or another tower?

Start with the problem your next upgrade should solve

Sentry is the machine-gun tower in the recorded opening tutorial. Its bullets travel toward the aim point you choose. Before spending Scrap, check whether that aim covers the route: an upgrade can change a tower’s output or placement allowance, but it does not move an off-path target onto the road.

For the three documented first-tier choices, separate damage per bullet, shots per second and the number of Sentries you may place. The diagram is an explanation of those different effects, not a recommended purchase order. The panel values below come from Random Roblox Games R US’s September 28, 2026 recording; compare them with your current Tech Tree.

Original guide diagram. These are three different upgrade effects; the drawing is not a game screenshot or an efficiency ranking.

Read the effect, purchase count and next price separately

In the reviewed recording, each of these nodes starts at 1 Scrap. Firepower I adds 0.16 damage per bullet, Rate of Fire I adds 0.48 shots per second, and Extra Sentry I increases the placement allowance by one. Those quantities have different units; comparing 0.16 with 0.48 alone does not tell you which purchase gives more useful damage.

Firepower I changes from 0/5 to 1/5 after a purchase. That fraction records purchases into this node, not towers built in the battle. Extra Sentry I has its own 0/3 counter and an explicit placement effect. After one purchase, the recorded next price for both Firepower I and Extra Sentry I becomes 3 Scrap. Do not multiply the initial price by the counter maximum to estimate the whole branch.

The Firepower I tooltip at 1:26 shows its effect, 0/5 counter and first purchase cost. This is dated creator footage, not a current-build price check.

An unlocked Sentry is not the same as completed upgrade branches

At 0:57, the Sentry Tower tooltip says Unlock, shows 1/1 and displays Fully upgraded. Read that message with the selected node’s name. It describes the displayed unlock node; it does not show that every Sentry improvement is complete.

The separate Sentry view at 1:25 contains Firepower I, Rate of Fire I, Reach I and Extra Sentry I around the central Sentry Tower / Back node. Subsequent panels show their own effects, counters and prices. For example, the Firepower I panel at 1:27 still shows 1/5 after the first purchase, while Extra Sentry I at 1:28 shows 0/3. If you are looking for stronger bullets or another permitted placement, inspect that named branch instead of stopping at the unlock tooltip’s Fully upgraded message. These are two views of the September 28 tree; the screenshots do not supply a complete current prerequisite map.

• 0:57 — Unlock, 1/1 and Fully upgraded ↗
• 1:25 — the separate Sentry upgrade branches ↗
• 1:27 — Firepower I still has its own counter ↗

Use a symptom check before buying

Choose one change you want to inspect on the next attempt. A second tower adds a placement and aiming decision; it is not the same action as making the first tower fire faster. If you change several things at once, a different result will be harder to attribute to one purchase.

Compare damage and fire rate with your own numbers

The recorded first Sentry tooltips use different units: Firepower I adds 0.16 damage per bullet, while Rate of Fire I adds 0.48 shots per second. A larger number does not by itself mean a larger increase in damage over time. The starting damage and firing rate matter too.

This calculator compares the ideal product of damage per shot and shots per second. Enter your current damage and rate, then the increments shown by the two nodes you are considering. The starting 1-damage and 1-shot-per-second values are invented examples; the 0.16 and 0.48 increments come from the September 28 recording. Replace all four values when your current display differs.

For damage D and rate R, the starting product is D × R. Adding damage increases it by the damage increment × R; adding fire rate increases it by D × the rate increment. The table shows why the same two increments can produce different comparisons. It assumes every shot hits for the entered damage and all other conditions stay the same.

• 1:26 — Rate of Fire I adds 0.48 shots per second ↗
• 1:27 — Firepower I adds 0.16 damage per bullet ↗

Add the next price to the damage-versus-fire-rate comparison

When two Sentry upgrades have different prices, compare the extra ideal output per Scrap as well as the total increase. The calculation above deliberately leaves price out. A more expensive improvement may add more output in one purchase while adding less for each Scrap spent.

Use D for your current damage per bullet and R for shots per second. Divide the damage upgrade’s gain, ΔD × R, by its displayed Scrap price. For the firing-rate option, divide D × ΔR by that option’s own price. Only compare prices expressed in the same resource; a cost in another resource cannot be put into a Scrap denominator without a supported exchange rate.

The exercise below invents starting stats and prices to isolate the decision. It uses the historical +0.16 damage and +0.48 shots-per-second increments from the September 28 recording. It does not describe a current Sentry save. With D = 1 and R = 3, either increment adds 0.48 to the ideal damage-per-second product. At different prices, however, their gain per Scrap differs.

After any purchase, read both stats and prices again. Raising damage changes the benefit of a later fire-rate purchase; raising fire rate changes the benefit of a later damage purchase. A single comparison cannot rank a whole branch. Accuracy, target coverage and time without enemies still matter, so treat this as a budgeting aid after fixing aim, not measured combat efficiency.

Correct the target before choosing a removal button

At 0:26, the recorded tutorial asks the player to tap the placed Sentry and drag its target onto the white dot on the path. The same screen shows two buttons: REMOVE and REMOVE ALL SENTRY. The second label explicitly refers to all Sentries; it is worth reading the full label before using a removal control.

For the off-path warning at 0:34, follow the target correction first: select the tower and drag the target onto the marked road. If the tower itself needs replacing, the desktop prompt also mentions right-clicking it to remove and place it again. Those instructions concern different objects: moving the target changes aim, while a removal action concerns a placed defense. This September 28 recording does not establish removal refunds, effects on other tower types or the controls used on every device. Follow the controls shown in your current game.

At 0:26, the target-adjustment prompt and the REMOVE / REMOVE ALL SENTRY labels are visible together. Historical creator footage; this saved frame was reread on October 19.

• 0:26 — compare the target prompt and removal labels ↗
• 0:34 — read the off-path correction ↗

Watch the description and the first purchases

Start with the Sentry description, then compare the cursor’s selected node with the tooltip beside it. Pause before and after a purchase to see which counter and price change. The chapters lead to the recorded panels rather than implying that the whole video is a single successful build.

If your current panel differs, use its displayed effect and price for your decision. This reference explains how to read the recorded choices; it does not establish a complete Sentry upgrade tree, a damage-per-Scrap ranking or the best setup for every level.

Buying damage and fire rate together changes the second comparison

If you plan one Firepower purchase and one Rate of Fire purchase, calculate the final pair of stats. Adding the two gains measured against the original tower misses the fact that the faster rate also fires the stronger bullets. This is an arithmetic consequence of the ideal damage-times-rate model, not a claim about actual hits.

Start with invented values of 1 damage per bullet and 1 shot per second. Use the historical increments shown in the September 28 panels: +0.16 damage and +0.48 shots per second. Damage alone changes the product to 1.16; rate alone changes it to 1.48. Taking both changes it to 1.16 × 1.48 = 1.7168. The combined increase is 0.7168, rather than the 0.64 obtained by adding 0.16 and 0.48 against the unchanged starting stats.

The additional 0.0768 is 0.16 × 0.48. In general, the gain from both purchases is ΔD × R + D × ΔR + ΔD × ΔR. You can use the existing calculator twice by entering the new stats after the first purchase. Read the actual next price again as well: the cost comparison is separate from this product.

If both final increments are fixed, their final mathematical product is the same whichever you apply first. That does not establish an equally useful purchase order in play. You may only afford one before the next battle, the next price may differ, and aim or restricted objectives can matter more than ideal output. Use the final-product check for a planned pair, and the current marginal gain for the single purchase you can make now.