A rune shard labeled "+9 Adaptive Force" can add 5.4 attack damage to one champion and 9 ability power to another. The label covers two different stat bonuses. One point of adaptive force grants either 0.6 bonus AD or 1 AP, not both.
The game chooses which stat you receive using its adaptive-stat rules. It does not inspect the spell you are about to cast and give that spell whichever stat would deal more damage. First identify the stat, then convert the amount.
This guide covers standard PC Summoner’s Rift. The adaptive shard gives 5.4 AD or 9 AP. The League Wiki's adaptive-force reference documents the selection rules and their exceptions.
How much AD or AP do adaptive shards give?
The current adaptive shard gives 9 adaptive force. It appears in both the offensive and flex rows, so selecting it in both gives 18. It is not an option in the defensive row. The current client rune records define those two slots.
| Adaptive force | If it grants bonus AD | If it grants AP |
|---|---|---|
| 1 | 0.6 | 1 |
| 9: one adaptive shard | 5.4 | 9 |
| 18: two adaptive shards | 10.8 | 18 |
Read across to the applicable stat column, not both columns. Two adaptive shards do not grant 18 AD, and they do not grant 10.8 AD plus 18 AP.
Multiply adaptive force by 0.6 for bonus AD or by 1 for AP. Equal adaptive force does not mean equal extra damage on a spell. An ability’s own scaling determines how much damage either stat adds.
Why buying an item can change the result
For straightforward flat-stat items, compare the bonus AD and AP eligible for the adaptive check. Higher bonus AD makes adaptive force grant AD; higher AP makes it grant AP. Do not compare total attack damage against AP: the attack damage your champion has as a base stat is not bonus AD.
Also, do not multiply your AD by 0.6 before making this comparison. The 0.6 multiplier converts the adaptive force after the stat is selected. It is not an exchange rate that makes 10 AD count as only 6 AD when checking your items.
Here is a simple inventory example, calculated on paper. It assumes two adaptive shards, no other relevant stat sources, and no stat multipliers. It is not a recommended shopping order.
Buy a Long Sword. Its current item stats give 10 AD. With 10 AD and 0 AP from items in this example, the shards supply 10.8 bonus AD. You now have 20.8 bonus AD from the sword and the shards together, in addition to your champion’s base AD.
Keep the sword and buy an Amplifying Tome. Its current 20 AP exceeds the sword’s 10 AD for this simple item comparison. The shards switch to 18 AP. You keep the sword’s 10 bonus AD and now have 38 AP from the tome plus the shards. The item stats are unchanged; the adaptive bonus moved.
Both components’ values are in Riot’s current item data. The selection rule comes from the specialist adaptive-force reference linked above.
Buying the tome can therefore make your attack damage fall even though the sword is still in your inventory. The missing 10.8 AD belonged to the shards, not the sword.
What happens at a tie?
A tie uses the champion’s predefined adaptive type. It does not universally default to AD.
Lux is a useful example: her current normal champion record specifies an AP adaptive preference. With no competing eligible AD or AP sources, her adaptive shards grant AP. That default does not lock her adaptive force to AP forever; a sufficient change in eligible stats can still switch the result.
The stat panel is not a universal shortcut
The comparison has exceptions. The specialist reference documents that AD and AP granted by champion passive effects do not themselves decide the adaptive type. Some item-passive grants also do not count, while others do.
That is why the example above uses plain Long Sword and Amplifying Tome stats. If your champion stacks stats or your build converts one stat into another, comparing the two headline numbers in the stat panel can give the wrong answer. Check how that specific source participates instead of assuming every point of displayed AP or bonus AD is treated identically.
You do not need to solve every item exception to choose ordinary shards. You do need to avoid turning "higher bonus AD or AP" into a promise that all possible sources are included.
The same adaptive bonus can affect spells differently
An AP ratio tells you that ability power contributes to an ability. It does not tell you that the ability deals magic damage. Similarly, an AD ratio does not automatically make an ability’s damage physical.
Ezreal’s Mystic Shot makes the distinction concrete. Its current normal calculation includes 130% total AD and 40% AP, while the spell deals physical damage. The coefficients and damage type come from the normal Ezreal Q record and its bound English tooltip.
Holding other modifiers fixed, consider only the extra raw damage on Mystic Shot itself from one 9-adaptive-force shard:
- If it grants 5.4 bonus AD, the Q scaling gains 5.4 × 1.30 = 7.02 damage.
- If it grants 9 AP, the Q scaling gains 9 × 0.40 = 3.6 damage.
Both amounts contribute to the spell’s physical damage. These are before-armor calculations, excluding on-hit effects and other damage, not observations from a match. They do not prove an entire AD or AP build is better; they describe one part of one ability.
Lux uses the AP differently
Lux’s Final Spark has a 120% AP ratio in its current normal spell calculation. If one shard supplies 9 AP, that adds 9 × 1.20 = 10.8 raw damage to the laser itself. The calculation has no AD ratio, so bonus AD does not increase that part of the spell. This example excludes any separate passive damage and other modifiers.
A shard’s label cannot tell you how much a particular ability gains. You still need to know which stat it becomes and whether the attack, spell, shield, or heal you care about has a ratio for that stat. If that effect has no ratio for the stat, this part of the upgrade contributes nothing.
Bonus AD does not increase Sheen’s base-AD scaling
Adaptive force that becomes AD grants bonus attack damage. It does not increase base AD.
Sheen’s Spellblade proc scales with 100% base AD, as shown by its current normal item calculation and the current Sheen reference. Adding a 5.4-AD shard does not add 5.4 damage to that separate proc.
The attack carrying Spellblade can still benefit from bonus AD. So can a spell that uses total or bonus AD in its own calculation. Keep those parts separate: an attack or Mystic Shot may get stronger while Sheen’s base-AD contribution stays the same.
Do not extend that rule to every completed Spellblade item. Read the particular item’s formula; another item can include different stats or coefficients.
Should you take two adaptive shards?
Two shards give more adaptive stats than one, but they consume two choices. In the offensive row, choosing adaptive means passing up attack speed or ability haste. In the flex row, adaptive competes with movement speed and scaling health. Compare what each choice changes in the lane or fight you expect.
If a trade usually gives you one spell hit before you back away, the stat that scales that hit has an immediate use. If your lane depends on repeated attacks, attack speed may help with the sequence instead. Extra raw damage is not automatically better than an additional attack opportunity, and extra attack speed is not useful if you cannot safely attack.
Start by identifying the attack or spell you want to improve. Check its scaling, then check what your adaptive force will become with your intended purchases. Choose the shard that improves the trading pattern you intend to use.