Game tick

Overview
The Runescape Clock is a term that is used to refer to the timeframe used for actions in Runescape. Runescape runs on units of time of approximately 0.6 seconds which are sometimes called "ticks." All actions are a multiple of this basic tick time. This includes any instant where a message appears in the chat box, any instant that xp is gained, and any instant that a monster spawns. It does not necessarily include animations or loading times.

Length of the Tick
The length of the tick can be measured by timing a repeated action using a stopwatch. For example, lighting 25 logs without relighting a log takes 100 ticks. If the stopwatch can be stopped to within 0.1 seconds, the tick can be measured to within 0.001 seconds.

Ideally, without any lag, there should be exactly 100 ticks per minute, or 0.600 seconds per tick. However, the observed length of the tick is actually slightly more than this, presumably because of some type of lag or delay. The observed length of the tick is usually about 0.606 to 0.608 seconds.

Length, in ticks of selected actions

 * Attacking with a whip: 4
 * Attacking with a Godsword: 6
 * Attacking with Dharoks greataxe: 7
 * High alchemy: 5
 * Superheat item: 3
 * Plank make: 3
 * Bake pie: 3
 * Stringing a bow: 2
 * Cutting a bow: 2
 * Burning logs: 4
 * Woodcutting: 4+
 * Fishing: 5+
 * Offering bones: 4
 * Fastest lap of Ape Atoll: 63
 * Putting a second into a potion: 2
 * Putting a herb into a vial: 1

Application
In general, knowledge of the RuneScape clock does not matter much, but it can make it easier to time actions. Timing just one of a repeated action may clearly give a tick number, which may be able to be used to estimate xp per hour.

When the high alchemy animation was changed, there was much argument about whether it was slower or faster. Based on the RuneScape clock, it should have been incredibly clear that the time was not changed, since if there was any change in the speed, it would have to be by a full tick and therefore be extremely noticeable.

Proof
A 0.6 second tick time fits all measured times for repeated actions.

Also, in April 2009, Andrew posted a thread about whether a prayer update caused delay in prayer being activated, and he brought up the point that if prayer really was slower, it would have to be a full 0.6 seconds slower because RuneScape runs on units of time of 0.6 seconds.