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Game Design In Theory

What Does Delta TTK Mean?

☰ Table of Content

Time To Kill

is a measurement of how long it takes for a player to defeat another player in a PVP game. It’s mostly used in the first person shooter sphere, especially in games with many players running around the same map. Games with high TTK, like Halo, can feel forgiving–or they can feel like they’re being played in slow-motion. Games with low TTK, like Counter-Strike, can be exciting and fast-paced–or they can feel exceptionally difficult, like playing chess against a grandmaster. At a speed measured in hundredths of a second.

Some games have wild swings in TTK. League of Legends, for instance, has fights that can last several seconds in the extremely early game, where your character has little to no upgrades and their slowest, weakest attacks. Toward the midgame and lategame, though, depending on which characters you’re playing and how successful you and your opponent have been in farming for those upgrades, you can reach a point where your opponent takes only a split second to kill you. Halo’s TTK varies wildly based on what guns you’re using and how accurate you are with them–the sniper rifle is a one-shot kill on a headshot, and the shotgun can be comboed into a melee strike to kill a nearby opponent in under a second, but hosing each other down with the AR before closing for a melee hit takes at least two seconds.

Other games have much smaller variation in TTK. Counter-Strike–already a game with extremely low TTK, where headshots with many guns are one-shot kills and predictable recoil patterns make extreme close quarters extra-deadly–has one of the smaller differences in TTK, from 1/3rd of a second with optimal use of the pistol to 0 with the AWP. Titanfall 2, like many loadout-based shooters, doesn’t necessarily give more successful players a lower TTK…unless they get ahold of a Titan, but that’s a whole different story.

And there’s also the question of how your TTK changes after a death. In Counter-Strike, or Quake 3, or many other classic multiplayer FPSes of the early 2000s, dying means starting from scratch. If you slip up and let another player get the better of you, you must now work your way up from the bottom of the power scale–either by saving money and playing smart in CS, or by frantically searching the map for resources in Q3. Dying as a pilot in Titanfall 2 doesn’t mean much, but dying in a Titan means a slow grind toward getting another Titan. Dying in League doesn’t set you back in stats, gold, or equipment; instead it costs you in terms of opportunities with respawn timers that range from several seconds to over a minute in lategame–long enough for your opponent to go back and buy a key item with the gold they got from that kill, or even worse, to simply finish the game while you’re staring at a grayscale screen.

Delta Time To Kill

is a term I’m coining for the sake of talking about this very concept. DTTK is the degree to which TTK changes in a game–typically, I’ll be referring to the difference in TTK between the player at the start of a game and the player at the peak of their power, i.e., a player with a glock versus a player with an AWP in Counter-Strike, or a pilot versus a Titan in Titanfall. That said, when talking about DTTK, it’s also important to note things like whether you can be worse off than when you start (i.e., in games where you can run out of ammo) or whether death resets your TTK entirely (as opposed to being a mere setback). Delta Time To Kill has drastic effects on how a game is played, and specifically affects how likely it is for a game to be an upset (that is, for a player who’s behind to win).


Low Delta TTK, TTK Resets On Death

Games with low DTTK, like Counter-Strike, encourage underdogs. While there’s still a difference between a player at max power and a player at start, the difference is small enough that a player who’s been winning for a while can’t afford to slack off. Since a death means a DTTK reset, and a player at minimum DTTK is still able to kill a player at peak power in as little as 1/3rd of a second, there’s a constant risk of the current leader being toppled by luck–or by skill. This creates the atmosphere of anticipation, where the clutch 1v5 is always tantalizingly within reach. That having been said, rising from the bottom to the top is still difficult–the DTTK isn’t zero, it’s just really small.

High Delta TTK, TTK Resets On Death

Halo and Quake 3 both have a relatively high delta-TTK–because both games feature relatively weak weapons on respawning and an emphasis on finding better weapons around the map. Both games also feature weapons that have drastically lower TTK, although Quake 3 doesn’t really have any weapon that has a TTK of zero in all circumstances, whereas Halo has the sniper rifle (which one-taps on headshot) and the Spartan Laser (which technically has a TTK of several seconds thanks to its charge-up time, but is also a one-tap). Halo also has the gravity hammer and energy sword, although IIRC the energy sword is only a one-tap on backstab. In any case, both of these games have a high delta TTK because the weapons strewn across a map are significantly more powerful than the ones you typically start with. That said, they also reset TTK on death, which leads players to play cat-and-mouse with enemies that are particularly strong, searching for resources while avoiding direct confrontation.

It should be noted that both Halo and Quake 3 have alternate game modes which drastically change the delta-TTK, which leads me to the next example:

Zero Delta TTK

Quake 3 instagib, custom Halo matches where everyone uses the Spartan Laser (or the Sniper Rifle with no shields), and games where players start with all of their available weapons (such as Team Fortress 2, or most loadout shooters) all have a DTTK of essentially zero. For the sake of argument, I’m going to set aside cases where a player unlocks more powerful guns through progression outside of the match. The point here is this: Some games, and some gamemodes, have effectively no difference in time-to-kill between players who are ahead and players who are behind. This makes the playing field nice and level, but it also means that the game lacks the “swinging pendulum” feeling of a game where winning grants some kind of advantage.

Negative Delta TTK

On the other hand, Mario Kart is famous for giving better items to players who are doing badly, creating a situation where the player in the lead is less powerful than a player at the start of the match or in last place. This tends to turn off players who value Challenge, as they see this handicap as undermining the role of skill in the game, rewarding players who are not as worthy of victory. However, forcing the player in front to rely on racing skill arguably makes the game more skillful; only someone who can take full advantage of the driving mechanics in Mario Kart can hold the lead for a lengthy period of time.

Positive Delta TTK, No Reset On Death

Finally, there’s games like League of Legends, where the delta TTK doesn’t reset on death, and the delta TTK changes per-match based on how far ahead the leading team is. I’m not gonna pretend that I have a thorough understanding of every possible combination of champions and gold leads; the important part is that in League, one death may not be enough to lose your lead. A team that’s far enough ahead can suffer a wipe and still have enough momentum–either via objectives or because of the resource cost involved in taking them out–that they can simply continue as before.

Why does this matter?

We can infer a whole bunch of things about a game from its DTTK. Games with low DTTK or negative DTTK reward underdog players for playing aggressively, while games with high DTTK reward underdogs who play cautiously and can avoid death for longer. Games with high TTK but low DTTK will feel like closer matches than games with high TTK and high DTTK. Games which don’t reset DTTK on death may reach a point of being unwinnable, while games which do reset DTTK on death will force the leading player(s) to play cautiously for fear of losing their precious advantage. Like I said in the Kinds Of Fun article, having terms to use when talking about this stuff is important for discussing more complicated questions, like what’s wrong with Minecraft’s combat or why League seems to be full of assholes (more on that later).

Update: 2021-06-10

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