Watching the above video made me think of Time to Kill and it’s relationship with fun. Is it more fun to kill a dragon in 5 minutes or kill 100 rats in the same period of time? What if the kills gave you the same rewards? What if the dragon or rats gave better rewards?
Time to Kill is an old measure used in games to figure out how long it takes for someone to clear an encounter (or simply an enemy). In D&D, TTK could be measured in hours. In the arcade games of yore, TTK was fractions of a second. The faster the TTK, the higher the adrenaline rush and sense of power. The longer the TTK, the more skill is required (typically) and the larger the sense of accomplishment at the end.
In the MMO sphere, WoW has exceedingly low TTK numbers for everything but raid bosses. Leveling, the TTK should be under 5 seconds for most classes. Dungeons are about 20s for a pack, 1-3 minutes for a boss. This is part of Blizzard’s arcade-feel and quite evident in the Diablo series, though much more so in Diablo 3. TSW has a 1minute TTK for most encounters. EQ1 was similar. Rift has a slightly higher TTK than WoW but it’s still pretty close. EvE’s TTK is measured more like D&D as the strategic elements often outstrip the value of power.
The actual value of TTK is important in the overall feel of the game. Too short and it the rush feeling of power simply goes away after a while. It feels like you’re passing a broom. Those games need meta goals, where the TTK is simply tool used to stretch out time to reach the goals. Too long and the player doesn’t feel powerful enough, sort of like an eternal mountain climb. In these games, the rewards between TTK have to be elevated to reward the risk.
The important factor, above all else, is consistent TTK. If the primary game mode has a consistent TTK with sporadic jumps, that makes those jumps feel special and the rewards should be appropriate. If for some reason that sporadic jump becomes a plateau and the rewards are based on the lower one, then you have a problem. D3 is a good example, where the TTK from 1-60 is rewarding. Level 60’s TTK actually inverts what you had before, extremely long TTKs with short bursts. However, the reward system is for the former. When this happens, people complain that they are losing power when compared to before and the game loses it’s fun appeal. From the Dev Notes for D3, it’s clear they want to address this problem.
In this regard, I think that as a fun metric, we can use TTK consistency. If the bar is stable with spikes spread out, then you have a nice combination of challenge and power. If the bar is 100% stable, then it gets repetitive quickly. If the bar is stable but has drops from time to time, those feel like amazing times. In all cases, the rewards for a given event should be directly related to the TTK of the event – otherwise people won’t bother.