This post explains how hit/miss chance is calculated in Splinterlands for melee and ranged attacks (this does not apply for magic attacks). It's actually quite simple!
Ok, for example, let's start with two melee monsters who have the same speed (for argument's sake let's say speed of 3). These two monsters, with equal speed, have a 100% chance to hit each other with a melee or ranged attack.
For every 1 point of speed difference between monsters,
a 10% miss chance is added. So a monster with 3 speed attacking a monster with 4 speed now has a 10% chance of missing the faster monster (or a 90% chance to hit).
A monster with a speed of 3 attacking a monster with a speed of 5 has a 20% chance to miss (80% chance to hit) and so on.
Abilities also come into play and compound hit/miss probability.
'Flying' and 'dodge' each add a 25% miss chance regardless of speed (when the monster being attacked has these abilities)!
The 'blind' ability imparts a 15% miss chance when the attacking monster is blinded (again regardless of speed).
For example a monster with 12 speed attacking a flying monster with 1 speed will ALWAYS have a 25% chance to miss because of the flying ability! The same holds true with dodge: there will always be a 25% miss chance when attacking a monster with dodge regardless of the speed difference. Blind will always add a 15% miss chance.
These abilities also compound, meaning when attacking a monster with flying AND dodge there will always be a 50% base miss chance!
When a blinded monster attacks a monster with dodge and flying, there is always a 65% base miss chance.
Add to this the speed calculation (10% per speed point difference) and you can calculate hit/miss probability.
So for example, a monster with 1 speed attacking a monster with both flying and dodge and 6 speed (a speed difference of 5, or 50%) has a 100% chance to miss!
If both monsters have flying, that 25% miss chance is negated.
If both monsters have dodge, there is no cancellation, the miss chance is always in play.
Understanding this concept is key, and you start to realize how compounding speed buffs for your team (and/or slow de-buffs for the other team) can have a huge impact on your gameplay and strategy. Try using a summoner with a speed buff (like Pyre) in addition to using fast monsters with flying and/or dodge, and also other monsters that offer speed buffs (or slowing de-buffs). When you stack these abilities the effect can be devastating to your enemy! This strategy can be highly effective in melee only or lost magic rulesets.
Don't forget how this works with REVERSE SPEED rulesets! Monsters with 1 speed become the fastest on the team!
It's important to remember that not only strategy (which is vital) but also RNG and luck are involved in each battle!