Chimera Squad Analysis: The Timeline

Broadly speaking, the Timeline is Chimera Squad's turn order mechanics, but it's also the informative graphic on the right side of the screen that shows current turn order, predicted turn order modifications if considering an action that interacts with the Timeline, what point in the turn ticks forward assorted effects not tied to individual unit turns (completion of a Round), and just generally is useful.

Among other points, it not only displays headshots for each unit, it displays their factional icon (Allowing you to ID Shrike units as distinct from your Investigation target's forces, though sadly the game fails to call the player's attention to the significance of the icons, somewhat undermining this utility. For reference, in the above screenshot the Necromancer has a Shrike stylized head icon to its left, while two slots below it is a Thrall with the Progeny's stylized hand icon), and if you hover over a given slot the camera will move to the unit in question (Ensuring that even if multiple copies of a unit type are running about you can readily determine which Thrall is about to act) and the Timeline slot will slide open to show both the unit's name and its current HP out of max HP. Even Armor and whether the unit is in High Cover will be displayed!

Anyway, I'm starting with talking about the Timeline before getting to agents and so on because Chimera Squad's turn mechanics are very different from what came before, and have a lot of non-obvious wrinkles the game doesn't really explain and that aren't necessarily intuitive. Instead of the player taking a turn with all their units, followed by the enemy taking their turn with all their units, then looping, each unit gets its own individual turn slot. (The Breach Phase is a notable exception, but I'll be covering that in detail in the next post)

The mechanics of where units get slotted into the Timeline is particularly non-standard. Chimera Squad doesn't have an 'initiative' stat (Well, actually it does, but I'll get to that) or speed stat or otherwise have unit turn order be controlled by comparing such internal stats the way turn-based games usually do when making turn order individual to units rather than operating at the level of overall faction. Instead it's... determined two different ways that are inherently intertwined.

The easy one is the player's end of things. Before an Encounter starts, the player makes decisions in regards to the Breach Phase. Again, I'm getting into that next post, but the relevant thing here is that the player decides on the turn order of their agents for the Breach Phase, and then this decides their relative turn order once the Encounter switches from the Breach Phase to the Timeline system: if Godmother leads the charge in the Breach Phase, then she's also the first agent to act after the Breach Phase, and if Cherub acted last in the Breach Phase, then he's the agent that acts last afterward as well, and so on. This is all intuitive and relatively obvious in playing the game.

Not so obvious and not explained by the game is how enemies get their turn placement decided.

First of all, Chimera Squad prefers to have agents alternate with enemies: if there are four enemies once the Breach Phase is over, then the turn order will be Agent 1, then an enemy, then Agent 2, then another enemy, and so on until enemy number 4's turn is over.

Of course, Chimera Squad doesn't stick stringently to 4v4 encounters, raising the questions of: what if there are more agents than enemies? And what if there are more enemies than agents?

When agents outnumber enemies, the procedure I laid out above still happens, and you just end up with agents acting back-to-back toward the end. That is, if there are three enemies, then Agent 4 will act immediately after Agent 3, then the Round is over and you go back to Agent 1 and loop the turns as they first were. (Assuming nothing changed turn order)

If there are more enemies than agents, then the game iterates the process: at 5 enemies, you will have 2 enemies act right after the first agent and before the second agent, and at 9 enemies you'll have three enemies act between the first two agents. (I have never seen 4 enemies between the first two agents without manipulating turn order; the game doesn't generate enough enemies in individual Encounters for it to happen)

A special note on this topic is that enemy reinforcements employ the same logic with no regard to the current number of enemies on the field nor to their respective turn positions. If three enemies reinforce in, they will insert themselves after the first, second, and third agents in turn order, even if eg two enemies are currently between the first two agents and no enemies between the other agents.

As for how order is determined for enemies relative to each other, every enemy has a hidden Initiative stat, where higher Initiative means they get placed earlier in the turn order by default. The game is surprisingly nice about this in that more elite, more dangerous enemies tend to have lower Initiative (Exception: all bosses have the highest Initiative and always go first out of enemies), so you have more time to respond to them...

... though this comes with the qualifier that it intersects oddly with the 'wrapping' effect. Say your squad burst into a room, and exactly 5 enemies survive the Breach Phase, one of which is an Andromedon, which has bad Initiative and so is normally toward the end of the enemy turn order. What the game does is assign the other four enemies, then the Andromedon ends up being the third unit to go in the entire Encounter because its turn position got assigned last and the wrapping ended up with the dead-last turn slot being the first post-wrapping slot assignment. So lower-Initiative enemies on average go later in an Encounter, but depending on exact enemy counts and so on the lowest Initiative enemy may actually be acting before 3 (Or more!) enemies that have much higher Initiative than it!

I suspect this isn't quite how the devs imagined the rules they came up with to work in practice, as for one thing it creates some odd incentive structures for a player who is aware of it. After all, initial enemy turn order is only decided once the Breach Phase is over, with all dead or Unconscious enemies not incorporated into the Timeline; if a player counts up all visible enemies in the room (And some Encounters are open enough spaces this is realistic to do with the first agent in spite of the Breach Phase limiting information access), they can see there's exactly 7 enemies and so decide to not quite finish any enemies within the Breach Phase so that that some low-Initiative elite like an Andromedon ends up slotted after the third agent, instead of taking out 2 enemies and causing them to be slotted after the first agent.

Anyway, returning to turn mechanics more generally, once the Timeline has been constructed all this stuff about the game trying to organize turns so your agents roughly alternate with enemies stops applying. (Aside the previously-covered reinforcements point) That is, when all units have taken their turn and a new Round begins, the game does not try to assemble a new turn order. Rather, turn order after that is simply that when a unit's turn ends, it gets slotted into the end of the Timeline in the next Round.

This by default will of course recreate the initial turn order if nothing happens to change turn order, but... the turn order isn't going to stay exactly as it was first constructed. For starters, when units go down, they're simply removed from the Timeline: in the screenshot above, that Necromancer going down before Verge's turn was over would result in Cherub acting immediately after him, and 'Cherub acts right after Verge' would continue to be true in later Rounds if nothing else acted on turn order. For another...

... Team Up is one of Chimera Squad's foundational player actions: once per mission, the currently active agent can pick another agent and move their turn to right after the agent using Team Up. Again, this change will persist: in the above screenshot, if Verge used Team Up on Blueblood, Blueblood's turn would be moved all the way from the next Round up to right after Verge, and then come next Round Blueblood would still be acting right after Verge even though that's not how their turns started out set up.

This isn't the only ability Chimera Squad has to manipulate the Timeline, either, and with one enemy-only exception they all persist in their consequences due to the 'your turn ends and you go to the end of the current Timeline' thing.

Also, it should be pointed out that all Timeline modifications work by changing relative turn placement. This isn't some wild, foreign concept if you've ever played basically any non-computerized turn-based game (A board game, for example), but for a video game it's actually really weird: video games usually (Often, invisibly) track all turns against a universal clock and in turn make any modifications be in relation to that clock. That is, in most video games with at all similar of a turn framework, doing something like delaying an enemy's turn would be something like applying a 5-unit delay relative to a universal clock, where if nothing was going to act within 5 units of their current turn such a delay won't have an immediate impact on the visible turn order.

Whereas in Chimera Squad, if an action delay's a unit's turn, that's in the sense that its current turn slot is moved further down the Timeline relative to other units: a delay of 2 is 'go after the 2 units that would otherwise have gone after you'.

A side effect of this is that delaying a unit whose turn is currently at the end of the Timeline will actually do nothing: you need to wait until other units have been placed behind them!

On a more local level, it should be pointed out any effect with a duration that is applied to a unit has its duration tied to a unit's turn. If you set an enemy on fire for 2 turns, and then they take 2 turns in the current Round, they burn twice and the fire goes out. Conversely, if you set them on fire for 2 turns and then use a bunch of turn manipulation actions to shove their turn to the end of the Timeline repeatedly, the fire won't hurt them and won't tick down its duration until they actually get a turn. I say a unit's turn because some effects aren't tied to the victim's turn, but the inflictor's turn, though this is much rarer.

In the case of ability cooldowns, these specifically increment at the end of a unit's turn. This matters because Chimera Squad has the very unusual concept of being able to gift a unit action points without giving it a real turn. If you have Verge use Stupor (Which has a 1-turn cooldown) and end his turn, then have another agent throw a Motile Inducer at him, he'll be able to immediately Stupor again. If you do in fact have him Stupor again, then when his next real turn rolls around, Stupor will be on a one-turn cooldown, because its cooldown didn't advance when he acted outside his own turn.

Do note that Team Up is manipulating the Timeline to drag the beneficiary's real turn forward; it doesn't experience any of this particular weirdness. But most effects that an agent can use to get allies to act sooner are just action point gifting and do have this not-entirely-obvious wrinkle in play. Among other points, it's generally better to spread around action point gifting rather than piling it all onto one agent.

Also note that, somewhat awkwardly, ability cooldowns are carried forward across Encounters. I call this awkward because it can lead to cases where it's optimal to stall so one or more agents can advance their cooldowns to prep for the next Encounter; if for example you have two agents who will go before the last enemy of the map and both have abilities on lengthy cooldowns, arranging for the latter of them to finish that last enemy is free cooldown advancement. I feel like the game should've at least had all agents with a turn left in the current Round automatically advance their cooldowns a turn when completing the Encounter to minimize the jank here.

Also, action point gifting actually lets you resolve the actions of all units with action points in whatever order you like. That is, if Verge uses a Motile Inducer to give Cherub 2 action points, the player is then free to have Verge use all his action points, or to have Cherub use all of his action points, or to have them alternate spending an action point apiece, or whatever. This contrasts with if two agents have back-to-back turns: if Verge used Team Up on Cherub instead, Cherub couldn't take actions before Verge was done acting. Among other points, action point gifting can lead to the slightly-unintuitive situation of an agent being out of action points but the game still considering it to be their turn because whoever they gifted action points to hasn't finished using those action points.

But the main point is to not forget action point gifting gives you flexibility on the order agents act.

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Overall, the Timeline is one of the bits of Chimera Squad that's most obviously tied up in being an experimental side game, and I would be quite surprised if XCOM 3 used it as the foundation of its turn mechanics.

I have mixed feelings about that fact as I quite like the Timeline and think using it as a foundation could potentially help resolve problems with the swinginess of pod activation and other problems the prior two games struggled with. Chimera Squad itself doesn't really illustrate the potential for such benefits, because its Encounter system essentially replaces pod activation, but the potential is there.

But it probably doesn't matter: experimental side games pretty much never have really major experiments like this become integral to later main entries, and indeed rarely even spin off into successive entries of their own. (That is, we're probably never going to see a Chimera Squad 2, or otherwise get more XCOM sidegames using the Timeline) Alas.

As far as Chimera Squad itself goes, the Timeline comes across to me like an attempt to circumvent the dynamic (that XCOM 2 embraced) where if the player is playing the game well the overwhelming majority of enemies will never get a chance to act. If so, it's not very successful an attempt; mastery of Chimera Squad still results in the player taking out or disabling most enemies before they get the chance to act. The route the player takes to arrive at that conclusion is a bit different, in that they end up prioritizing targets higher in the Timeline for initial attempts to take out or disable rather than reliably prioritizing whatever enemies are most dangerous to leave running about or targeting whichever enemies are easiest to take out (Which are the two primary metrics one employs in XCOM 2), but even on the highest difficulty of Chimera Squad it's very possible to get through most Encounters with most enemies never getting a turn at all. (And most of the ones that do technically get a turn not getting to do anything with it, because the player Stunned them, disabled their weapon, correctly assessed them as a non-threat that wouldn't accomplish anything with its turn if left alone...)

When first learning Chimera Squad's systems, it looks like more of a give-and-take combat model where enemies acting is an expected part of play, but... well, that's true of XCOM 2 as well, where a learning player gets to see enemies do things because they don't yet have the game mastery to reliably stop that from happening.

That said, I wouldn't be surprised if the Timeline was never imagined as escaping the 'never let any enemy act' dynamic. Chimera Squad's tuning is such that letting enemies act can go very wrong very quickly; agents don't actually have that much HP compared to enemy firepower, for example. So for one thing, even if the initial impetus behind the Timeline was 'can we escape this dynamic?' the devs seem to have been fine with the game developing in a manner pretty contrary to that impetus.

Whatever the goal behind it, the Timeline is an interesting experiment, and in most respects it's put together surprisingly well. I'd have expected it to have a lot more 'this wasn't really thought out' sorts of problems, honestly.

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Next time, we move on to agents, starting with Verge.

See you then.