Extra Orb is a rare card in The Tower: Idle Tower Defense. It adds another orbiting orb to your defence, giving you an extra way to kill enemies before they reach your tower.
Extra Orb
When equipped, Extra Orb gives you a spinning orb that destroys enemies on contact. Bosses are the exception — the orb does not destroy them, so it will not carry you through boss waves on its own.
The card's listed speed value determines how fast the orb spins. Check the table below for the exact values at each level.
| Card Level | Effect |
|---|---|
| 1 | .30 |
| 2 | .40 |
| 3 | .50 |
| 4 | .60 |
| 5 | .70 |
| 6 | .80 |
| 7 | 0.90 |
Card Mastery
Unlocking the Extra Orb card mastery costs 750 stones. Once unlocked, it grants an orb coin bonus, increasing the coins you earn through your orbs.
The bonus is only active while Extra Orb is equipped in your active loadout, so you need to keep the card slotted to benefit from it.
| Mastery Level | Value |
|---|---|
| 0 | x1.04 |
| 1 | x1.08 |
| 2 | x1.12 |
| 3 | x1.16 |
| 4 | x1.2 |
| 5 | x1.24 |
| 6 | x1.28 |
| 7 | x1.32 |
| 8 | x1.36 |
| 9 | x1.4 |