Gameplay Basics
How Do Doubling, Swapping and Might Changes Work?
Doubling and swapping calculate fixed modifiers from the values when the action happens.
RiftPal explanation · Answer first
The short answer
DoubleIncrease a value by its current amount when instructed, for the effect's stated duration. Doubling a negative value adds 0.View in Glossary adds an amount equal to the current value when the action happens; it does not keep doubling later changes. SwapExchange two numeric values by adding their difference to the lower value and subtracting it from the higher one for the instructed duration.View in Glossary adds the difference to the lower value and subtracts it from the higher one. Those modifiers last for the effect's stated duration, so later bonuses or penalties still change the result.
RiftPal explanation
How it works
Use the values when the action happens, not when its target was first chosen. If a swap starts with equal values, it changes nothing.
A non-passive effect with a minimum or maximum remembers the amount it could actually change at that moment. This is called a SnapshotThe fixed increase or decrease remembered by a non-passive arithmetic effect after applying its minimum, maximum or other limitation when it happens.View in Glossary . For example, reducing a 2 MightMight represents both how much Combat Damage a unit can contribute and how much marked Damage it can normally take before being killed.View in Glossary unit by 4, to a minimum of 1, creates only a -1 modifier. Later increases do not turn that modifier into -4. A continuing Passive AbilityAn ability that applies automatically while its conditions are true, without being activated or put on the Chain.View in Glossary does not take this snapshot; its required increase or decrease is recalculated as the situation changes.
Setting Might to a number is different from increasing or reducing it to that number. A set value applies before arithmetic bonuses and penalties. In the arithmetic layer, Might increases apply before decreases, with dependencies determining relevant ordering within the layer.
Might can be negative. Use the actual negative value for calculations that increase or decrease Might, including swapping; treat it as 0 when an ordinary spell or ability reads its Might or when adding combat damage. Doubling negative Might adds 0, because an instruction to increase a value cannot increase it by a negative amount.
In practice
Example
Card example
Last Stand
Example 1 - Doubling a temporary total
A unit has 3 base MightMight represents both how much Combat Damage a unit can contribute and how much marked Damage it can normally take before being killed.View in Glossary and Shield 2 while defending, for 5 Might. DoubleIncrease a value by its current amount when instructed, for the effect's stated duration. Doubling a negative value adds 0.View in Glossary its Might this turn adds a fixed +5, bringing it to 10. After combat, Shield stops applying: 3 base Might + 5 from doubling = 8 Might for the rest of the effect's duration.
Spell
Last Stand
[Action] (Play on your turn or in showdowns.) Double a friendly unit's Might this turn. Give it [Temporary]. (Kill it at the start of its controller's Beginning Phase, before scoring.)
Card example
Switcheroo
Example 2 - Swapping values
An effect swaps two units' current MightMight represents both how much Combat Damage a unit can contribute and how much marked Damage it can normally take before being killed.View in Glossary of 2 and 5 this turn. The difference is 3, so the first gets +3 and the second gets -3. Their Might becomes 5 and 2. If the first then gains another +1 Might, it becomes 6; the swap does not keep forcing it back to 5.
Spell
Switcheroo
[Hidden] (Hide now for [Rainbow] to react with later for [Energy 0].) [Action] (Play on your turn or in showdowns.) Swap the Might of two units at the same battlefield this turn.