Fuzzy Dice

Info
Fuzzy Dice give your tank a percent chance for each of its attacks to be a "critical hit", which causes double damage.

Note that, with no Fuzzy Dice equipped, your tank has a 0% chance of landing critical hits.

The chance that a given instance of damage is a critical hit or not is dependent on the attack itself, not the tank being attacked. An attack that hits multiple targets will either be a critical hit against all of them or none of them.

This upgrade stacks with other instances of itself; two common Fuzzy Dice give you an 8% chance to deal double damage, not two 4% chances that could both trigger at the same time for quadruple damage.

Common
+4% critical chance

Rare
+8% critical chance

Epic
+12% critical chance

Strategy
A +4/8/12% chance to deal 100% more damage is mathematically the same thing as +4/8/12% more damage 100% of the time. Compared to a Bullet, with its +5/10/15% more damage, Fuzzy Dice deal slightly less damage over time, so use this upgrade on tanks with a Special that can score critical hits or when you want to keep your damage output unpredictable.

Note that a critical hit doubles the total damage of an attack, not just the base value. This means that there are situations where, on average, Fuzzy Dice will offer a larger boost to damage than other upgrades of the same rarity.

Stinger, Titan, Tower, Scorpion and Kong all have Specials that can benefit from Fuzzy Dice (though Scorpion's special damage is so small as to be negligible).

Joker, Buck, Ninja, Gatlyn, Phoenix and Arachno have Specials that deal damage, but cannot score critical hits.

Morty, Wally, Sparky, Scarab and Shift have Specials that do not deal damage at all and thus cannot score critical hits.