Level is the level of the tower. For double path towers, they do not need to have either A or B next to them as the tabs above the template will usually be enough to tell them apart.
Evolution Level is the evolution level that the upgrade is unlocked on. Any upgrades unlocked by default should be set to 0. This should only be included on evolved towers.
Upgrade Title contains its upgrade name. Prior to the Overhaul Update, not every tower had upgrade names, meaning that it is not included everywhere.
Cost is the cost of the upgrade.
Image is the icon for the upgrade.
Information contains the statistical changes for the upgrade. Additionally, it also contains the changed sell cost of the tower at the very bottom.
Narrator if not specified, will randomize an image that sits on the bottom right of the container, however, it will not appear on mobile. A list of values can be found here.
Examples
{{Upgrade|Upgrade Title = Level 3 - Watch Your Step - {{Money|3,500}}|Image = [[File:TrapperLevel3.png|100px]]|Information = +10 Spike Damage [[File:Damage Icon.png|20px|Spike Damage]]
5.508 > 5.008 Spike Firerate [[File:Cooldown Icon.png|20px|Spike Firerate]]
+1 Range [[File:Range Icon.png|20px|Range]]
+1 Max Traps
+Landmines [[File:TrapperLevel3.png|20px|Landmine]]
•65 Damage [[File:SplashDamage.png|20px|Landmine Damage]]
•3 Burn Damage [[File:Damage Icon.png|20px|Burn Damage]]
•6.008 Firerate [[File:Cooldown Icon.png|20px|Landmine Firerate]]
•0.5 Tick [[File:Cooldown Icon.png|20px|Tick]]
•8 Range [[File:Range Icon.png|20px|Landmine Range]]
•6 Explosion Range [[File:ExplosiveRange.png|20px|Explosion Range]]
•0.5 Burn Time [[File:Cooldown Icon.png|20px|Burn Time]]
Sell Price changes to {{Money|2,000}}}}