Tower Lab Tower Tier List

This is a pre-launch ranking of the 20 Tower Lab towers. Steam Early Access is scheduled for September 7, 2026. It is demo-informed and playtest-informed. It is not an official balance sheet, and it will move after launch. There are no DPS numbers here because the game has none. Robots have no health. A cube ranks high when its physics job is easy to plug into a machine.

Read the tower roster for roles. Read tower synergies before you buy a second S-tier name that does not share a job. First-run hands belong on starter decks.

Caveats before the tables

• Tesla looks like S on copper and much worse on rubber. Playtests removed Tesla from the Region 1 starting deck.
• Grow is A as a robot scaler and S as a projectile scaler. The letter below is the cube, not the verb.
• Deflector sat at the bottom of at least one playtester list before the rework. After bombs, mines, and units could bounce, it climbed.
• Gravity once captured units forever; projectile lifetime was rebalanced. The rank assumes the rebalanced well.
• Constructor and Grinder rank as production. They lose waves that have no knockoff edge.
• Synergies beat isolated S-tier. A C-tier Imploder in a full well can beat a lonely Rocket.

S tier

S-tier cubes create jobs for the rest of the board. You draft them because they make other cubes better, not because they “kill” faster.

Tower	Why it sits in S
Gravity	Orbits enemies and projectiles. The hold that turns Pulse, Bomb, and Fan into a spiral.
Fan	Directional gusts that push or slow. The shove that finishes Shrink and drives a Gravity spiral.
Shrink	Lightens mass so any shove becomes a knockoff. The cheapest leak fixer in the roster.
Tesla	High knockback arcs, copper first, stackable Double Strike and chain. Rubber is the caveat.

If you can only keep two S cubes, keep Fan and Shrink on a tight map, or Gravity and Fan on a map with a pit. Tesla is the greedy third when the region’s material agrees.

A tier

A-tier cubes are strong once a partner exists. They are the usual shop buys that complete a machine.

Tower	Why it sits in A
Grow	More Matter and more risk on robots; more force on projectiles. The verb is S, the cube is A until you have a finisher.
Deflector	Redirects projectiles, mines, and units. Plumbing for Bomb, Mine, Kinetic, and Split lines.
Kinetic	Gravity-immune knockback orbs. Barricades with Deflector. Shotgun trap with a second Kinetic and a Fan.
Bomb	Explosive projectiles and area knockback. Grows and bounces into a lab-wide shove.
Grinder	Turns robots into Scrap. A Conveyor Line off the output is the actual combo.
Split	Halves mass and copies the object. Factory loops with Grow and Deflector.

Grow plus Bomb is the greedy payload. Kinetic plus Deflector is the safe payload. Grinder plus anything that aims Scrap is the economy payload. Split is A only if you are willing to build the loop. A Split with no Grow and no bounce is a novelty.

B tier

B-tier cubes are useful and honest. They ask for a map, a hand, or a tech-tree hit before they feel like A.

Tower	Why it sits in B
Pulse	Timed knockback beats. Excellent in a Gravity well, quieter as a lone metronome.
Mine	Deployable knock mines. Climbs hard with bounce modules and Deflector conveyors.
Harpoon	Yank off the path. Wins on heavy bodies and loses on crowded files with no line of sight.
Rocket	Ballistic explosives. Wants Grow, bounce, or a long loft. Short lanes favor Bomb or Mine.
Cryo	Chills motion so a later shove can finish. Needs Fan, Pulse, or Tesla.
Constructor	Grows the lab instead of shoving. Pairs with Grinder. Slow if you are already leaking.

Pulse is the sleeper. If Gravity is already on the board, Pulse behaves like A. Constructor is the opposite sleeper: it behaves like C on a leak and like A on a stable factory. Rank it B so you do not skip it in Campaign, and so you do not first-pick it in a panic.

C tier

C-tier cubes are specialists. Draft them when the machine already has hold and shove, and you need a weird verb.

Tower	Why it sits in C
Flame	Thermal status. Changes how mass slides. Does not knock by itself.
Bola	Snare and bind. Time-buyer for Fan or Harpoon, not a win condition.
Merge	Fuses mass. Easy to create a heavier leak. Shines in Scrap and projectile factories.
Imploder	Inward collapse. Needs a cluster, which usually means Gravity already did the work.

C is not “do not play.” A Flame that sets up a Fan, a Bola that holds a grown robot for Matter, a Merge that packs Scrap, or an Imploder that dumps a well off a ledge is a correct card. C means do not open the starter decks page and first-pick these names.

How the letters move

Copper raises Tesla. Rubber lowers Tesla and raises Deflector, Fan, and sometimes Flame or Cryo if temperature becomes the lever. Pits raise Gravity. Long lofts raise Rocket. Factory maps raise Grinder, Constructor, Split, and Merge. Tight corridors raise Harpoon and Bola.

If you want a single sentence for the Vend-O-Lab: buy the partner for the cube you already placed before you buy a second letter from the S row. Gravity wants Fan. Fan wants Shrink. Tesla wants copper and a backup shove. Grinder wants a conveyor plan. Grow wants a payload. That sentence is more useful than memorizing the tables.

For module order once the partner is down, use upgrades and tech trees. For the loadout under the cubes, use cores and machines. For the parts list behind every letter, stay on the tower roster.

At the next Vend-O-Lab, ignore the urge to collect letters. Buy the cube that fills an empty job in your hold-shove-lighten-cash loop, even if that cube is B. Then take starter decks if the loop still has a hole going into Region 2.