Earthquake Spell: Backfire Chance Explained
The Earthquake spell is a powerful ability that can destroy up to 15% of a target kingdom’s basic buildings (excluding castles) when successful. However, if it fails, it may backfire, destroying 5% of the caster’s own buildings instead. The chance of a backfire depends on the Kingdom Strength (KS) ratio, calculated as the target’s KS divided by the caster’s KS (targetKS / casterKS). Below, we explain how this works in simple terms.
How Backfire Chance Works
The KS ratio determines how likely the spell is to backfire, making it riskier to cast Earthquake on kingdoms stronger than yours. Here’s how the backfire chance is set:
KS ratio ≤ 1.333 (target’s KS is up to 1.333x the caster’s):
0% backfire chance. Casting against kingdoms with similar or slightly higher KS is safe, with no risk of backfire.
KS ratio ≥ 2 (target’s KS is 2x or more the caster’s):
100% backfire chance. Casting against a much stronger kingdom will always backfire, damaging your own buildings.
KS ratio between 1.333 and 2:
The backfire chance scales linearly from 0% to 100%. For example:
A KS ratio of 1.5 (target’s KS is 1.5x caster’s) gives roughly a 25% backfire chance.
A KS ratio of 1.75 (target’s KS is 1.75x caster’s) gives roughly a 62.5% backfire chance.
The game rolls a random number (1 to 100) and compares it to the backfire chance percentage. If the random number is less than or equal to the backfire chance, the spell backfires.
What Happens on a Backfire?
If the spell backfires:
The spell fails to damage the target’s buildings.
5% of the caster’s basic buildings (excluding castles) are destroyed, distributed proportionally across building types.
The caster sees a message like:
"Your Wizards failed to cast Earthquake—and it backfired, destroying [number] of your own buildings!"
The target is notified:
"[Caster’s kingdom] attempted Earthquake on you, but it misfired and damaged their own holdings."
What Happens on Success?
If the spell doesn’t backfire and succeeds (based on a separate success chance), it destroys a portion of the target’s basic buildings, capped at 15% of their total. If the target’s KS is less than 70% of the caster’s, the damage is reduced to reflect their weaker infrastructure. Both players receive messages, such as:
Caster: "Your Wizards successfully cast Earthquake, destroying [number] of [target’s kingdom]’s buildings."
Target: "[Caster’s kingdom] cast Earthquake on you, destroying [number] of your buildings."
Strategic Implications
The updated backfire mechanism makes Earthquake a strategic choice:
Safe Zone: Casting on kingdoms with a KS ratio of 1.333 or less (e.g., target’s KS is up to 1.333x yours) has no backfire risk, making it a safer option for attacking slightly stronger or weaker kingdoms.
High-Risk Zone: Casting on kingdoms with a KS ratio of 2 or higher guarantees a backfire, so avoid targeting much stronger kingdoms unless you’re willing to lose 5% of your buildings.
Risky Middle Ground: For KS ratios between 1.333 and 2, the backfire chance increases as the target’s KS grows relative to yours. For example, attacking a kingdom 1.5x stronger has a moderate risk, while one 1.75x stronger is much riskier.
This system encourages players to target kingdoms closer to their own strength, as attacking significantly stronger kingdoms (KS ratio ≥ 2) is almost certain to backfire, while attacking those with similar or slightly higher KS is safer.
Why This Change?
Some players were exploiting Earthquake to repeatedly target much larger kingdoms, disrupting game balance and fairness. By setting the backfire chance to scale with the KS ratio (starting at 1.333 and reaching 100% at 2), we ensure that attacking stronger kingdoms carries significant risk. This promotes thoughtful strategy, discourages abuse, and keeps the game enjoyable for all players by rewarding balanced matchups.
