Some item effects are documented by community-maintained lists rather than a current official item database. Where the available sources do not confirm a drop rate or exact platform behavior, this guide says so instead of treating an estimate as fact.
Fast answer
The answer before the background
Open the mission loadout before a battle and assign collected items to their matching tower types. Each selected item passively modifies every tower of that type that you build in the mission. There are 42 commonly documented tower-item effects across Gun, Inferno, Laser, Cannon, Meteor, Missile, Concussion, Tesla, and Temporal towers. Rewards are random after completing missions, so no reliable mission guarantees a particular item. Choose effects according to the aliens and map layout: shield breakers for shielded enemies, reveal effects for stealth, slowing effects for long lanes, and area damage for clustered waves.
How the system works
What counts as equipment
These are not character weapons or a conventional inventory. They are tower loadout items: passive modifiers selected before the mission begins. The item is attached to a tower category, not to one individual tower. For example, a selected Laser item affects every Laser tower you build during that battle.
The official game descriptions confirm that the game has more than 40 tower upgrades with five power levels each. Community documentation identifies 42 shipped effects in the base item pool. The exact strength of a higher-level item depends on its in-game level, so compare the displayed effect and level rather than assuming every upgrade has the same value.
- Select the mission and open its loadout.
- Assign a collected item to the matching tower category.
- Start the mission and build that tower normally.
- The effect applies automatically; no activation or Boost Tower is required.
- Items are separate from AI special weapons and from Steam trading cards.
| System | How it is used | What it changes |
|---|---|---|
| Tower item | Equipped before a mission | A tower type’s shots, targeting, damage, status effect, or utility |
| AI special weapon | Selected with a command team or AI loadout | A powerful active ability available through the chosen AI |
| Trading card | Collected through the platform service | No tower combat effect; it is a platform collectible |
The passive, pre-mission behavior is consistently documented. Random post-mission acquisition is also documented, but a current official source does not publish a complete reward table or exact odds.
Item database
All documented tower-item effects
The following list groups the documented effects by tower. Names may vary slightly with localization or older community wording, so use the effect description shown in your copy of the game as the final authority.
- Gun: Shield Piercing Bullets ignore shields and damage the alien directly; Target Strongest Always changes targeting priority; Shield Disrupting Bullets add damage against shields; Scatter Shot creates a short cone attack with reduced range; Chemical Tipped Bullets apply damage over time; Tachyon Bullets slow the target.
- Inferno: Target Strongest Always prioritizes the strongest alien; Concentrated Fire tightens the cone and increases damage; Napalm applies damage over time; Shield Eroding Chemical Spray improves shield damage while reducing other damage; Torch Bearer spreads fire to aliens that make contact.
- Laser: Target Strongest Always prioritizes the strongest alien; Tachyon Beam increases the slow effect while reducing damage; Wide Beam adds area coverage with lower-range damage; Shield Piercing Beam bypasses shields; Shield Disrupting Beam increases damage against shields.
- Cannon: Anti-Stealth Ordnance reveals stealthed aliens near impact; Target Strongest Always changes targeting priority; Chemical or Drill Tipped Ordnance applies damage over time; Tagger temporarily reduces the target’s speed; Anti-Shield Ordnance improves shield damage; Cluster Cannon Ordnance adds an area cone; Airburst adds area damage at impact.
- Meteor: Fireball increases heat damage over time; Target Strongest Always changes targeting priority; Plasmaball extends damage-over-time duration while reducing area damage; Cluster increases area-of-effect range.
- Missile: Target Strongest Always changes targeting priority; Chemical Tipped Warhead applies damage over time; Temporal Missile slows the target after impact; Bonus Damage Versus Fastest improves damage against fast aliens; Shrapnel increases area coverage.
- Concussion: Fire Bombs ignite targets for damage over time while reducing physical damage; Anti-Shield Bombs improve damage against shields; Depth Charges reveal stealth around the blast with reduced damage.
- Tesla: Depth Charger reveals stealth aliens hit by the chain; Target Strongest Always changes targeting priority; Anti-Shield increases shield damage; Damage-over-Time Charge leaves a charge that can pass to contacting aliens.
- Temporal: Increased Slowdown makes the pulse slow enemies more strongly but at a slower pulse rate; Bonus Versus Core Carriers improves damage against core carriers; Loose Core Speed Booster makes loose cores move faster while in range.
| Problem | Useful item families | Reason |
|---|---|---|
| Shielded aliens | Shield Piercing, Shield Disrupting, Anti-Shield | Either bypasses shields or removes them faster |
| Stealth aliens | Anti-Stealth, Depth Charger, Depth Charges | Reveals hidden targets so other towers can attack |
| Fast aliens | Tachyon, Temporal, Tagger, Bonus Damage Versus Fastest | Creates more firing time or improves direct counter-damage |
| Large groups | Scatter, Wide Beam, Cluster, Airburst, Shrapnel | Adds area coverage or multi-target damage |
| Core carriers | Temporal Bonus Versus Core Carriers | Focuses extra pressure on enemies that threaten the objective |
Target Strongest Always appears in several tower pools. It is a targeting preference, not a universal damage increase, so it is strongest when a dangerous heavy alien must be killed before weaker targets.
Acquisition and setup
How to earn and equip items
Specific tower items are reported as random rewards after completing missions. There is no verified fixed mission that always awards a named effect. That means the practical way to build a collection is to finish missions you can win consistently, then inspect the reward and loadout screens after each result.
The available evidence does not establish a dependable public drop-rate table. Difficulty, map choice, and mission duration have been suggested by community sources as factors that may influence reward quality, but treat those claims as unconfirmed rather than guaranteed rules.
- Complete a mission in any supported mode that awards a result.
- Check the reward screen and your item inventory.
- Open the next mission’s loadout before pressing start.
- Assign only the item that answers that map’s main threat.
- Swap items between missions; the choice is not permanent.
- If you are hunting one effect, replay short, reliable missions rather than risking long failures.
| Loadout goal | Recommended approach |
|---|---|
| General campaign progress | Use one shield answer, one crowd-control answer, and one stealth answer where available. |
| A long single lane | Favor slow effects, Target Strongest Always, and damage over time. |
| Open maps with many routes | Use area effects only where enemies reliably overlap; otherwise choose direct damage or reveal effects. |
| Challenge scoring | Test the same item setup against the mode’s rules because some challenges disable or restrict equipment. |
A higher-level item is not automatically best. An area effect can be worse than shield damage on a shield-heavy mission, while a reveal item may be essential on a stealth-heavy route.
Recommendations
Best use cases by threat
Start by identifying the enemy mechanic that is costing you lives. Shield effects are valuable when ordinary fire is being absorbed. Reveal effects matter only when stealth is present, but they can restore the usefulness of the rest of your defense. Slow effects become stronger when the map gives towers a long firing lane or when enemies pass through several boosted positions.
Damage-over-time items are most useful against durable targets that remain in range. Area effects are strongest when the route compresses enemies into a predictable group. If enemies spread across several paths, a single-target item or a targeting priority may produce more dependable results.
- For shield waves, test Shield Piercing on Gun or Laser and Anti-Shield options on Cannon, Concussion, or Tesla.
- For stealth waves, use Cannon Anti-Stealth, Tesla Depth Charger, or Concussion Depth Charges.
- For fast aliens, combine slowing effects with a long lane instead of relying on raw damage alone.
- For dense groups, compare Cluster, Airburst, Scatter Shot, Wide Beam, and Shrapnel according to the tower’s range.
- For core carriers, use the Temporal bonus and protect the lane with complementary slowing or damage towers.
| Recommendation type | Evidence status |
|---|---|
| Items are passive after equipping | Verified by consistent game guides and the documented loadout behavior |
| There are more than 40 tower upgrades | Verified by official store descriptions |
| There are exactly 42 base effects | Documented by a shipped-item community list; not presented as a current official database count |
| A particular map guarantees a particular item | Not verified |
| Exact drop percentages | Not published in the sources reviewed |
The official store listing describes six AI characters with unique special weapons. Those abilities should be planned separately from tower items because they are selected and used through the AI or command loadout, not assigned as passive tower modifiers.
FAQ
Common questions
How many tower items are in the game?
The commonly documented base pool contains 42 tower-item effects across 10 tower types. The official store wording confirms more than 40 tower upgrades, but it does not publish the complete named list.
Do tower items need a Boost Tower?
No. A selected tower item is a passive modifier. Build the affected tower normally, and its effect is active without placing a Boost Tower beneath it or triggering a separate button.
Can I farm a specific item from one mission?
No fixed mission guarantee is verified. Available community documentation describes specific item rewards as random, so replaying a reliable mission is the safest farming approach, but it cannot guarantee a named result.
Are the six AI weapons part of the item database?
They are related equipment, but they are not tower items. They are special weapons tied to the AI or command-team system and should be listed separately from passive tower upgrades.
Which item should I equip first?
Use a counter to the map’s dominant threat. Choose shield damage for shielded waves, reveal effects for stealth, slowing effects for fast enemies or long lanes, and area damage when enemies reliably cluster.
Sources
What we checked
Official listings establish current availability and product facts. Community pages are used for mechanics and build history, then labeled separately.
- OfficialNintendo official product page, tower upgrades and AI special weapons
- OfficialHidden Path Entertainment, Defense Grid 2 product and update information
- OfficialSteam product page, current features and platform details
- CommunitySteam community discussion, shipped tower-item list
- CommunitySteam community guide, item behavior and acquisition notes