Cost and effect

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The year is 2015 and you’re in the last round of swiss at a local store championship. It’s turn 3 and you have your Lady installed, but it’s out of counters. Luckily, you have Scavenge in your grip. You raise your hand and yell “JUDGE!”, causing your opponent to levitate briefly. The judge arrives, and you ask: “Can you please confirm that I am allowed to play Scavenge here even though my heap is empty?” “Yes indeed, you are”, says the judge after glancing at your grip. “Thank you kindly”, you say and proceed to reinstall your Lady using Scavenge, as your opponent nods in acknowledgement.

What is going on?

Few rules concepts in Netrunner are as controversial as “no change in game state” (“NCIGS”). Plenty of new players have butted their heads against this occasionally unintuitive idea, and many have questioned its relevance and utility. I want to talk a bit about how this rule works, what it means, and what would happen if it was removed.


Update 2022-12-04

  • Some CR page references were incorrect and have been fixed. (They were inconsistently referencing the clean and annotated versions of the document. Now all references are to the clean document.)
  • Clarified what the consequences of the Scavenge errata were.

What is NCIGS?

Netrunner has a rule that says you can’t play a card or use an ability if it won’t have an effect. This is colloquially known as the “no change in game state” rule (often abbreviated “NCIGS”). At first glance, it might seem quite innocuous and intuitive. “You can’t do a thing if it doesn’t do anything.” Makes sense to me! But this simple idea can lead to some surprising results.

Let’s take a look at the specifics. The “NCIGS rule” is not actually a single rule - it is mentioned in several places in the NISEI Comprehensive Rules (CR) - but the main codification of the concept is in section 1.2, “The Golden Rules”:

CR 1.2.5 A player can only take an action or use an ability if its effect has the potential to change the game state. This potential is assessed strictly by what the action or ability can be expected to accomplish, without regard to the consequences of paying any costs to initiate that action or ability and without regard to any other abilities that may meet their conditions in the process of initiating or resolving that action or ability.

That’s a bit of a mouthful. Let’s pick it apart.

A player can only take an action or use an ability if its effect has the potential to change the game state.

This means that you can’t play Diesel if there aren’t any cards left in your stack, or use the basic action to pay two credits and remove a tag if you have no tags.

This potential is assessed strictly by what the action or ability can be expected to accomplish, without regard to the consequences of paying any costs to initiate that action or ability…

The second part of the rule clarifies that even though playing a card might cause obvious changes like your credit total going down when you pay the cost of the card, these changes are irrelevant to the evaluation of NCIGS.

…and without regard to any other abilities that may meet their conditions in the process of initiating or resolving that action or ability.

And thirdly, you don’t consider changes in game state that might result from other abilities triggering off of things happening during the resolution of the ability you want to use, or after it. (Like Rejig being trashed after use, causing Aniccam to draw a card for you.)

Diesel Aniccam

This general formulation of the concept is then further expanded on in a few other sections of the CR. They don’t really add that much more detail, and serve mostly to specify exactly which actions and abilities are subject to NCIGS, but I’m including them here for completeness’ sake:

CR 5.2.4 A player can only take an action if its effect has the potential to change the game state. See rule 1.2.5.

CR 9.1.5b When determining whether a certain ability has the potential to change the game state, look only at the expected effects of the ability. Do not consider its costs or restrictions, and do not consider other abilities that could become pending or relevant because of triggering or resolving the ability. See rule 1.2.5 of the Golden Rules.

CR 9.1.6d A player can only use an ability if its effect has the potential to change the game state. See rule 1.2.5.

CR 9.6.7d A conditional ability with a static condition can only be marked pending if the instructions in the ability have the potential to change the game state.

In summary, NCIGS is applied when you want to (examples in parentheses):

  • Perform an action (playing a card, installing a card, drawing a card, making a run)
  • Trigger a paid ability (fetching and installing a program with SMC, breaking subroutines with Corroder)
  • Resolve an optional ability (putting a counter on Conduit after a run, trashing an ice with Hippo)
  • Trigger a conditional ability with a static condition1 (trashing Dadiana Chacon when you have 0 credits, trashing an ice with Parasite)

What about conditional abilities without specifically static conditions? Not governed by NCIGS. If you make a successful run with DreamNet installed and no cards in the stack, the ability still triggers and draws zero cards.


Does NCIGS mean that I can’t perform an action if some of its effects can’t happen? Not quite. There’s another Golden Rule in Netrunner that you always try to do as much of an effect as possible:

CR 1.2.4 If an instruction does not include the words “if able,” as much of that instruction as possible is carried out. Any parts of the instruction that are not possible to carry out are ignored.

This means that you can still play cards like Diesel even if you have only two cards left in the stack. You simply draw those two cards and you’re done. NCIGS is only fulfilled if the effect wouldn’t change anything at all. Thus, if you have no cards left in the stack, 1.2.5 overrides 1.2.4 and forbids you from playing the card.

“But hey now”, you say, “I have some convoluted reason to want to get this Diesel out of my hand right now. It’s important.”2 No can do I’m afraid! Drawing 0 cards is not a change in game state3, and while the trashing of the event after resolving is itself clearly a change in game state, remember that the NCIGS rule only looks at the text on the card, not the framework surrounding the playing of it. “But what about VRCation? That costs one credit to play, that’s a change in game state right?” It sure is! But again, the rule doesn’t care. It only looks at what the result of resolving the effect itself would be, not at costs or other effects triggering off of the paying of costs.


This is where the fun starts. Certain cards have costs that are quite intricate. Simulchip is the classic example. Its additional cost pulls double duty. It imposes a limitation on when the card can be used, but it can also function as an enabler for the ability itself, by trashing a program that you then immediately reinstall. How convenient!

A typical use case is trashing a Botulus and reinstalling it on another piece of ice. However! NCIGS demands that we look only at the results of resolving the effect of the ability when determining if the ability may be used or not. So let’s look at a common game state: It’s early in the game, you haven’t actually trashed any cards yet; the heap is empty. You have a Botulus installed on a piece of ice in front of HQ, and a Simulchip. You run R&D, and when the corp rezzes their Ice Wall, you want to pop Simulchip to trash the Botulus and reinstall it on Ice Wall instead.

Simulchip Botulus

But you can’t.

NCIGS only looks at the effect, which is to install a program from the heap. There’s no program in the heap, so the effect does not have “the potential to change the game state”. “But that’s preposterous” you say, “obviously Botulus will be in the heap when the effect resolves and I’ll be able to install it”. Yes, this is obviously the case. But NCIGS doesn’t care, it doesn’t look at the results of paying costs. If you had some other program in the heap beforehand - a Rezeki, let’s say - NCIGS agrees that the effect has the potential to change the game state, and will allow you to trigger the ability. You are now free to trash Botulus and reinstall it just like you wanted. You’re not required to actually install the Rezeki, it just had to be there for NCIGS to give the green light.

Simulchip is very similar to the now long rotated card Scavenge. Its original wording had the same type of additional cost language that resulted in the same kinds of locked situations where you were forbidden from playing it, with the additional complication of that card allowing you to install a program from your grip as well, so it was valid to play Scavenge with an empty heap if you had a program in your grip. How could your opponent know that this was the case? Well, they just had to trust you, or you could ask a judge to come over to look at your hand and confirm that you could legally play Scavenge.

This was considered very tedious and countless players undoubtedly misplayed this interaction without ever being aware of it. Eventually, the card received errata that completely rewrote the ability to have the trashing be part of the effect instead of the cost, which caused NCIGS to not apply anymore4. This was one of very few times that FFG issued an errata to a card simply to improve the usability. In almost all other cases, errata was reserved for cards that had omissions, misprints or (in extreme cases only) were in dire need of rebalancing.

Scavenge AstroScript Pilot Program

Paying costs can also be the trigger for other abilities. The most well-known examples are Geist and Tech Trader (often played together, now both rotated). After a cost is paid there is a checkpoint, allowing conditional abilities to trigger in between the paying of the cost and the resolution of the ability’s effect. Going back to Simulchip, let’s imagine we want to use its ability to install an Engolo, a pricy card at 5 credits. It’s the only card in your heap, having been trashed earlier the same turn, so there is a valid target for Simulchip. You, however, are broke. Luckily, you have two Tech Traders installed that will give you 2 credits when you trash Simulchip, and the ability itself gives you a 3 credit discount, so that should cover it! Alas, no. NCIGS ignores game state changes triggered by the paying of costs, and determines that you are 2 credits short of being able to pay for Engolo, so you can’t trigger the ability.

Geist Tech Trader


NCIGS is not universal. It applies specifically at the point of the timing sequence where you choose to take an action, trigger a paid ability or trigger a conditional ability. Once an effect has started resolving, NCIGS doesn’t care anymore. This means that you can sometimes walk right past it and perform exactly the kind of “nonsense” plays the rule is seemingly designed to prevent. For example: Cards with effects directing the user to do something a certain number of times or spend a quantity of something allow you to choose the number 03. Take Mutually Assured Destruction. Because of NCIGS, you are not allowed to play it unless you have at least 1 rezzed card in play. But if you do fulfill that condition, you may play it and then choose to trash 0 cards. This will give the runner 0 tags and is a perfectly legal play.

There is another type of effect which frequently trips people up, and that is increasing the strength of icebreakers. It is, in fact, completely legal to increase the strength of an icebreaker at any point, using their native pump abilities or abilities from another card (like Takobi), even if it does you no good at all. This includes outside a run, or even on the corp’s turn. This has recently become very relevant due to the interactions of cards like Mantle and The Twinning, where you might be interested only in the side effect and not the primary ability at all.

Mutually Assured Destruction The Twinning

An icebreaker typically retains any strength gains from abilities until the end of the current encounter5, but strength increases outside of runs are reverted almost immediately, in the next checkpoint6. “In the next checkpoint” is not the same as “instantly” though, and such a strength increase is still considered a change in game state. This is not actually an exception to the NCIGS rule. It has to work like this, or it would be very hard indeed to use icebreakers! Consider how most icebreakers have separate abilities for breaking and increasing strength. The expected usage is to first use the strength-increasing ability, and then use the break ability once you have enough strength to interface. If increasing strength on its own was not considered a change in game state, icebreakers would be functionally unusable. (Or they would all have to be worded in ways similar to Paperclip and Black Orchestra.)

Is shuffling your deck a change in the game state? It is. You are allowed to trigger shuffle effects like that of Spin Doctor even if you don’t actually choose any cards from archives. Causing R&D to be shuffled is sufficient. This makes sense when you consider that cards like Daily Business Show (or the runner accessing the top card) may have caused cards in R&D to have known positions, and shuffling will obviously change that state. Search effects like Mutual Favor operate under the same logic (remembering that you can even voluntarily fail to find a card when searching if all you want to do is shuffle your deck, but only if searching for cards with specified criteria7, meaning Project Atlas does not give you this opportunity).

A final example: Overclock is a simple card. It enters play, you put some money on it and then make a run. During the run you can spend the credits. There are abilities that may prevent or forbid you from making runs though, like Peace in Our Time. Can you still play Overclock if such an ability is in effect? Yes you can. Placing credits on a card in play is a change in game state, even though you can logically conclude that nothing productive will come of it.

Overclock Peace in Our Time

Clearly, NCIGS can’t completely protect us from using cards and abilities for no effect. It can both prevent seemingly legitimate use cases (like Simulchip switcheroos) and allow completely nonsensical plays (like playing Overclock after Peace in Our Time). Whatever is it for? Find out after this short break!


The CR contains a single explicit exception to the NCIGS rule:

10.1.2a The Corp can always use a purge effect, even if there are no virus counters currently hosted on any cards. This is an exception to rule 1.2.5.

Crystal clear. This is needed because there is a class of cards with the text “when the Corp purges virus counters, trash this”. Why do these require an exception? That sounds like a change in game state to me! Indeed it is, but again: NCIGS is evaluated “without regard to any other abilities that may meet their conditions in the process of initiating or resolving that action or ability”. It’s not just costs and abilities triggered by costs that are not taken into account. Abilities triggered by the resolution of the effect itself are also ignored.8 So far, the various rulemakers of Netrunner have not found a better solution for this conundrum than to simply allow purging in spite of NCIGS.


So why is NCIGS important? Why do we need this inconsistent beast of a rule which only serves to confuse and perturb honest runners?

The oldest ancestor to the modern NCIGS rule can be found in FFG FAQ 1.4, from early 2014:

Triggering Actions
A player cannot trigger an action unless he [sic] is also able to resolve it.

This was amended later the same year in FAQ 1.5 to also refer to abilities:

Triggering Actions and Abilities
A player cannot trigger an action/ability unless he [sic] is also able to resolve it.

The fully evolved NCIGS rule was then added to the game a year later, in FAQ 2.2:

Triggering Actions and Abilities
A player can only trigger an action or ability if its effect has the potential to change the game state. This potential is assessed without taking into account the consequences of paying play, install, or rez costs or triggering any further abilities.

This is the form it would retain for the rest of FFG’s tenure, until being replaced by NISEI’s very similar wording in version 1.0 of the Comprehensive Rules.

FAQ 2.2 came out a few months after Geist was printed (but before Tech Trader), and a popular explanation is that the main reason for the expanded ruling was to prevent Geist from unduly exploiting cheap trash effects like Fall Guy and Shiv.

Another prominent card in the same pack as Geist (The Underway, SanSan Cycle) was Street Peddler, for which the most common rules question always was: “If Street Peddler has only events hosted on it, can I still trash it to release them into the heap or are they stuck there forever?” By now you know enough to answer that question yourself.9

Fall Guy Street Peddler

Why didn’t the designers want the player to be able to do things like this? There are two main lines of reasoning that can lead to that conclusion:

  1. It’s not good for balance. Geist can exploit cheap trash effects and draw way too many cards way too easily. (With the later addition of Tech Trader, which caused you to also make money from trashing your cards, this argument got even more popular.)
  2. It’s philosophically wrong. We want people to play cards because of what the effect of the card is, not to exploit side effects in a way that makes the card effect itself secondary. That’s just a design goal we have. (Consider: Cyberdex Sandbox recently got banned.)

We don’t have an official reason for the rule’s existence, but the fact that the full rule was introduced only after Geist and Street Peddler were released could be an argument for 1). On the other hand, Geist wasn’t a particularly strong ID until much later, after Tech Trader and a few other cards lifted him from obscurity. There were also the early incarnations of the rule which seem to indicate a similar intention even if they were not as precise and wide in scope, which could imply that 2) is a larger factor.

In conclusion: We don’t really know.

Alternate universes

What would happen if we just removed the NCIGS rule(s)?

There would be many small consequences, and a few larger ones. In the category of “probably fine” we have:

  • You could trash your hand at will with Citadel Sanctuary.
  • You could freely trash installed cards with Endless Hunger. (The similar cards Heartbeat and Dummy Box would not be usable for this purpose, since they are interrupts.)
  • You could remove virus counters from Botulus in anticipation of the corp playing Reverse Infection.
  • 24/7 News Cycle could be used with no “when scored” abilities to target just to conjure advancement counters with Jemison Astronautics - which just turns it into a worse Sacrifice though.
  • Simulchip would finally work like people expect it to (like Scavenge after the errata).

Somewhat more spicy are these two, which could potentially be argued to be “too powerful”:

  • Geist could draw cards and generate money even more flexibly than is already possible, making him even more of an economic tornado as well as having improved flatline protection.
  • False lead could be used at any time (including when the runner is at 1 click, losing them 0 clicks) to place advancement counters with Jemison. In particular, this would allow you to trivially execute a Drago + Boom! kill combo, as long as you have a False Lead scored beforehand.

Can you come up with something worse? Let me know! This classic Reddit thread didn’t really produce any mindblowing examples either.

Where we are

NCIGS is one of those perennial rules quirks that keeps vexing people to this day. Some have very strong opinions about it, while others feel it’s an obvious and completely uncontroversial rule. The fact that FFG issued errata to Scavenge many years after its release just to get people to stop asking how it worked might be an indicator that there’s something fundamental about NCIGS that screws with our heads somehow. Given that history, it surprised some that NISEI chose to print Simulchip, which made sure we had a reason to continue arguing about NCIGS even after Scavenge, Geist and Street Peddler had all rotated.

There is an intrinsic friction between printing cards whose costs are functionally part of their effects, and having a rule that ignores costs when evaluating whether the game state could change or not. This basic pain point is unlikely to change. However, apart from Simulchip, NISEI has printed very few cards which run directly afoul of NCIGS all on their own this way. (We’ll talk about The Class Act and its errata odyssey another time.) But Simulchip will rotate from Startup at the end of this year, and with that, at least the risk of new players getting frustrated by that particular gremlin mostly goes away. NCIGS is gradually turning into a thing of the past, right?


A challenger appears

The new Midnight Sun ID Ob Superheavy Logistics presents a dizzying array of entirely new ways to get confused about NCIGS! You can score the agenda Azef Protocol, paying the additional cost to trash an installed card which will trigger Ob, fetching a card to overinstall the Azef Protocol and… not score it. Or you can use the trash ability on Reconstruction Contract to trigger Ob10, fetch a card like Urtica Cipher and move the counters from Reconstruction Contract to it, even though it wasn’t even in play when you triggered the ability. Watch out though! Because there has to be another advanceable card installed somewhere for NCIGS to accept this. Which one? The runner will just have to trust the corp on that.

Or they could call a judge to confirm.

Ob Superheavey Logistics Reconstruction Contract

Appendix A: What is the “game state” anyway?

The phrase “game state” is mentioned 33 times in the NISEI Comprehensive Rules, but none of those instances is a definition of the term. It is a concept which we have to accept a priori, and its meaning is supposedly obvious. An intuitive definition could perhaps be something like: “the game state is the collection of all objects, abilities and information about current and past events and states affecting those objects and abilities relevant to the game of Netrunner currently being played”.

Are currently unused tokens in the supply part of the game state? The CR does define the concept of “the bank” which is a public zone where all currently unusued tokens reside. So maybe? Does that mean that adding new tokens to the bank from outside the game is a change in game state?

Cards that have been “removed from the game” are in a special zone known as the “removed-from-game zone”. This is different from being “outside the game” which means not being in any zone. (Cards like Rebirth and DJ Fenris interact with cards “outside the game”.) Is “not being in any zone” the same as not being part of the game state? No one knows.

Appendix B: Not created equal

Another interesting quirk was pointed out to me after the rest of the article was already written, that I still wanted to share. The quirk is this: Events and operations are treated differently from other cards and abilities when evaluating NCIGS.

For most basic actions, you simply look at the right side of the ability and see if it can be resolved, disregarding the cost, as usual. The basic actions are all normal paid abilities, defined in the CR like this:

CR 5.2.7 Corp Actions
a. The following BASIC ACTIONS are always available to the Corp during their action phase, in addition to any actions provided by card abilities.
b. “[click]: Gain 1[c].”
c. “[click]: Draw 1 card.”
d. “[click]: Install 1 agenda, asset, upgrade, or piece of ice from HQ.” See section 8.5.
e. “[click]: Play 1 operation from HQ.” See section 8.6.
f. “[click], 1[c]: Advance 1 installed card.” See section 1.18.
g. “[click], 2[c]: Trash 1 resource. Take this action only if the Runner is tagged.” See section 10.5.
h. “[click][click][click]: Purge virus counters.” See section 10.1.2.

CR 5.2.8 Runner Actions
a. The following BASIC ACTIONS are always available to the Runner during their action phase, in addition to any actions provided by card abilities.
b. “[click]: Gain 1[c].”
c. “[click]: Draw 1 card.”
d. “[click]: Install 1 program, resource, or piece of hardware from the grip.” See section 8.5.
e. “[click]: Play 1 event from the grip.” See section 8.6.
f. “[click]: Run any server.” See section 6.
g. “[click], 2[c]: Remove 1 tag.” See section 10.5.

Can you click for a card? Yes, if there are cards to draw. Can you install a card? Yes, if you have an installable card in hand and can pay its install cost. Can you play an event or operation? Yes, if you have one in hand and the play ability of that card would itself cause a change in game state. For events and operations only, NCIGS evaluation goes one level deeper than in all other circumstances. If this wasn’t the case, everything we’ve said about not being able to play Diesel with no cards in the stack - and similar situations - goes out the window.

While this nuance isn’t covered by the rules, neither is the exact definition of what constitutes a change in game state to begin with (see appendix A), so while it might seem inconsistent, there is room in the ruling praxis for this contingency.


This article uses the NISEI Comprehensive Rules Document version 1.6, which was released on 22 July 2022.

Rules mentioned:
Chapter 1: Game Concepts
1.2.4 (p.5)
1.2.5 (p.5)

Chapter 3: Card Types
3.9.5b (p.39)
3.9.5d (p.39)

Chapter 5: Turns
5.2.4 (p.51)
5.2.7 (p.52)
5.2.8 (p.52)

Chapter 8: Card Manipulation
8.7.2 (p.82)

Chapter 9: Abilities
9.1.5b (p.85)
9.1.6d (p.85)
9.6.7d (p.98)
9.12.2b (p.114)
9.12.2d (p.114)

Chapter 10: Additional Rules
10.1.2a (p.117)

Cards mentioned:
Dadiana Chacon
AstroScript Pilot Program
Tech Trader
Mutually Assured Destruction
The Twinning
Black Orchestra
Spin Doctor
Daily Business Show
Mutual Favor
Project Atlas
Peace in Our Time
Fall Guy
Street Peddler
Cyberdex Sandbox
Citadel Sanctuary
Endless Hunger
Dummy Box
Reverse Infection
24/7 News Cycle
Jemison Astronautics
False lead
The Class Act
Ob Superheavy Logistics
Azef Protocol
Reconstruction Contract
Urtica Cipher
DJ Fenris
Bloo Moose
Rashida Jaheem
NGO Front

The Underway, pack in the SanSan Cycle
Netrunner Rules team, Twitter account
Cards that are trashed on purge
Android: Netrunner FAQ v1.4
Android: Netrunner FAQ v1.5
Android: Netrunner FAQ v2.2
NISEI Comprehensive Rules 1.0
NISEI Standard Ban List 22.08
Magical Netrunner, Reddit thread


Beta reading

Proofreading & factchecking
114141 (Anna)
Cephalopod Wizard

Also thanks to


  1. A “static condition” continuously checks for a certain state, as opposed to a “trigger condition”, which is listening for a particular event to occur. 

  2. Maybe you’re running Bloo Moose and have already removed all the cards in your heap from the game. Getting one more card in there in order to get 2 credits at the beginning of your next turn is absolutely critical to your game plan and clicking for credits will just not be enough. 

  3. CR 9.12.2b Some abilities calculate a quantity using phrases like “for each”, “for every”, or “plus”. When a quantity is calculated this way for any of the purposes listed in rule 9.12.2c11, the resulting effect is aggregated to the value that was calculated. Only a single instance of that effect takes place. If the calculated value is less than or equal to 0, the effect does not take place at all.  2

  4. “Trash 1 installed program. If you do, install 1 program from your grip or heap, paying Xcredit less. X is equal to the install cost of the program you trashed.” 

  5. CR 3.9.5b Paid abilities on an icebreaker that modify that icebreaker’s strength implicitly have a duration of “for the remainder of the current encounter”. 

  6. CR 3.9.5d If an icebreaker’s paid ability modifies its strength outside of an encounter and does not specify another applicable duration, the modification expires during the next checkpoint. 

  7. CR 8.7.2d If a player is searching a deck for one or more cards with specified criteria, they may choose to fail to find anything, even if one or more cards matching the criteria exist in that deck. 

  8. The removal of virus counters is an explicit part of the purging effect itself, not a triggered ability, and thus passes the NCIGS test. 

  9. They are stuck there forever. 

  10. Reconstruction Contract would be another example to bring up in our NCIGS-free alternate universe; it could be used as a pure tutor card in Ob, fetching sweet 0 cost cards like Rashida Jaheem and NGO Front without having to put in the work of doing meat damage to put counters on it first. 

  11. CR 9.12.2c The following effects are aggregated when performed in a single instruction, as described in rule 9.12.2b4: gaining, losing, or spending a number of credits; gaining, losing, or spending a number of clicks; taking, removing, or preventing a number of tags; taking, removing, or preventing a number of bad publicity; looking at or revealing a number of cards from a specified location; drawing a number of cards; trashing a number of cards from specified locations (including by damage); and shuffling a number of cards from a player’s discard pile into their deck. 

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