From High Normal rarity cards onwards, there are cards with skills which will affect battle vs other players or vs event bosses by giving Boosts or Hits on specific stats. Using them to enhance will give a chance of increasing the skill level which is scaled according to the rarity and evolve state of the material card.
Your deck can get boosted by the effects from Skill Cards, cards whose realm matches yours, and bonuses from your order.
Hits work directly in the opposite way of Boosts - lowering the stats of enemy cards instead of raising your own.
 Skill activation
- When you attack only skill cards with attack skills can activate (boost your atk or hit enemy def). For example "Great hit to foe's DEF (all)" will reduce the enemies defense and "Big boost to gods ATK" will increase the atk of your god cards.
- When you are defending only skill cards with defensive skills can activate (boost your def or hit enemy atk).
- Skill cards which affect both atk and defense, like "Massive boost to ATK/DEF (all)", can go off in both cases.
- A maximum of 3 skill cards can activate during a battle. You can make a deck which consist of identical cards and they will still go off. For example, when you have 2 Apsara in your defense deck, both can activate and will work properly. An exception are Holy War point booster cards. When you have multiple skills cards that boost your holy war points in your deck (like Chiron) and one of them activates during a fight, another one of those hw point booster cards cannot activate anymore (other skill cards can).
- Whether a card's skill fires depends on its slot in the deck. (Slot 1 = center, Slot 2 = left center, Slot 3 = right center, Slot 4 = far left, Slot 5 = far right)
- The 1st skill card in your deck has a 100% chance to go off.
- After the first card activated, each subsequent skill card has a 50% base chance to go off. When the next card doesn't go off, the next one after this has this 50% chance until one of the activates.
- After 2 skill cards have been activated, each subsequent card has a 25% base chance to go off.
- If a card is skilled, add 1% per skill level to the base probability.
- For each time the current skill card has already activated, the probability is then reduced by half (1/2 x base% after 1 dupe, 1/4 x base% after 2 dupes)
- Finally, if no duplicates, including current skill card and previous cards, have activated, add 1% per skill level to the firing probability.
- See link for more details.
- The dmg including the boosts and hits is calculated like this (applies to def in the same way):
card atk * leader * order * (realm + skill boosts + trait skill boosts - skill hits + morale)
- It has to be calculated for every card individually.
- you have to round up after each multiplication to get the absolute correct value. When you don't round up, you may end up with a difference of 5-10 stats from the real value.
- the card has 1000 atk.
- you have the 5% atk leader bonus.
- Your order has the lvl 3 order building (7%). Example: the card is demon realm and you have the demon order building.
- the card matches with your realm (5%). Example: you and the card are god realm.
- you have 2 boost to atk skills, one gives 10% the other one 5%. That results in a total boost of 15% (It is NOT 1.1*1.05!).
- the enemy hits your atk for 15% (That is NOT substracted after your deck achieved all of your boosts).
- you have 30% morale bonus (you can get this, when you perform successful attacks on other players before)
atk *leader*order * (realm+ boosts - hit +morale) = 1000 * 1.05 * 1.07 * (1.05 + 0.1 + 0.05 - 0.15 + 0.3) = 1000 * 1.05 * 1.07 * (1.35) = 1516.725 (1518 with rounding up after each multiplication)
Calculators: There are some calculators available which can calculate things like that for you:
- Deck calculator by biuken
- Deck calculator by robsnap
- Deck calculator by ecksofa
- Deck calculator by Grun
 Skill strength
- Alignment boost 5% (Realm boost) - Each card in your deck whose realm matches yours gains 5% ATK when attacking and 5% DEF when defending.
- Order Attack Leader 5% (Leader boost)- If your order has designated you as an Attack Leader, your deck gains a 5% boost to ATK.
- Order Defense Leader 5% (Leader boost) - If your order has designated you as a Defense Leader, your deck gains a 5% boost to DEF.
- Order Join Effect 5-7% (Order boost)- If your order has the correct Order Buildings, realm matching cards will get a 5-7% boost for both DEF and ATK, depending on the building level.
- Victory boost 10%, 21% or 30% - Randomly start at 10% after a successful attack then randomly increase percentage after other successful attack. Effect for 10 minutes.
- Changes that have taken effect since Holy Wars -Rebirth-
- Order Leader 5% - Order Leader, your deck gains a 5% boost to ATK and DEF.
- Vice-Leaders 3% - If your order has designated you as a Vice-Leader, your deck gains a 3% boost to ATK and DEF.
- (This is subject to change without notice.)
For cards that have skill effects, each skill level beyond Level 1 increases the boost effect by 1%. From level 9 to lvl 10 it will be increased by 2%. For levels 11-14 different rules apply, based on the skill strength.
- For the record all the above percentages have been successfully verified within the discussion using clean, controlled tests. If you wish to make any changes to any of these percentages please use controlled conditions with no other bonuses calculated at all then post all finding data within the discussion page before changing. Thank you.
 Trait skill strength
Trait skill effects are boosted by 0.5% per skill level. The table shows the level 1 effect: Skill level boost seems to be linear, verified at least up to level 11. So a skill lvl 10 small boost to a trait's ATK gives (10-1) * .5 + 5 = 9.5% boost.
 Main skill boost percentages
As said earlier, skill level boost is non-linear from skill level 10 - 14: