Evil Dave's Spice of DOOM

Each colour spice affects different skill levels by giving them a temporary increase or reduction, similar to taking a potion except that the effects are random every time. The number of doses added of a colour will determine how much the skills affected by that colour can gain or lose, as noted in the table. This is the maximum number of levels gained or lost. For example, if a stew contains two doses of red spice, each of the skills affected by red spice may gain or lose between 0 and 4 points. A player can also try putting doses of different colours into the same stew to get an extremely variable concoction. You do not need to make a full 4 colour spicy stew; you only need to add the spices you particularly want to boost your stats which can be 1 dose of 1 colour only if you desire, whereas Evil Dave's Spicy Stew takes all 4 coloured spices and needs to be approved by Evil Dave. You can make and eat spicy stew with only 1 dose of 1 colour in it.

Note: the maximum positive skill boost for eating multiple spicy stews cannot exceed the maximum boost for one stew of that type. (see Eating multiple stews below)

The skills affected by each colour of spice are as follows. Note that Summoning, Constitution, Prayer, and Dungeoneering are not affected by any of the spices.

Eating multiple stews
Only one spicy stew can be made at a time, but the player can have several normal stews in their inventory along with several spices and mix the next one right after consuming the previously-made spicy stew.

As with all player temporary skill boosts, spicy stews will not boost higher than the player's natural skill level plus the (maximum) regular boost amount. For example, eating stews with only one spice will never boost a skill by more than two levels. However, multiple negative boosts can add, taking the player's skill level as far down as zero. Additionally, limited testing suggests that, unlike the way potions work, if the stew would have boosted a skill beyond the upper limit, then instead of boosting only to the upper limit and stopping there, the stew simply does nothing to that skill. This makes sense because otherwise a player who obtained a small boost in a skill (either by eating a stew or by using another skill boost such as a Crafting potion or mature Greenman's Ale) would have a greatly increased chance of then getting to the maximum possible boost by quickly making and eating a 3-dose stew. This would make it very easy to get the maximum +5 boost in almost any skill. The limitation means that already having a small skill boost from a stew makes no difference to the chance of getting a large one.

For example, if the player starts with a skill level of 50 and takes several 2-dose spicy stews, the effects could be something like:

Due to this, it is wise to have several lesser stat-boosting items to neutralize the effect of negative stews. When using this technique, it may also be useful to use a stat-boosting summoning familiar (or a restorative one, such a Bloated leech with Blood drain scrolls). Super restore potions are a more expensive option. As with other stat effects, logging out and then logging in does not restore stats to their original levels.

This boost gain limitation also applies to other player temporary boosts. However, some other boosts will stack with spicy stews, although not many. Crystal saws stack with stews (and with any other boost) because they do not actually boost your level; they simply allow you to build most constructed items as if your skill were three levels higher than it actually is, so they can be used with spicy stews for a maximum possible boost of +9 (as against +6 when the saw is used with tea, since tea gives an additional boost of only +3 even if you have the highest-level shelves in your kitchen - however, tea does make a good construction-stat recovery if your stew gives you a minus boost instead of the plus boost you wanted).

When trying to obtain a boost, it is important to note where the timer is for your skills to decay back to their normal levels. Prepare the stew and then switch to the Skills display and wait for a skill you already have boosted or reduced to change by 1 point. You then have 60 to 61 seconds before the next tick, so immediately eat the stew and you have the maximum time to use any positive effects it gives you. If you are simply smithing the helm for your Varrock Achievement Diary, doing this will let you avoid the risk that you might obtain exactly the boost you need, only for it to tick down before you can touch hammer to anvil. If you are boosting your Herblore, it will allow you to make the maximum number of potions before your skill boost fades away. Logging out to the lobby and logging back in resets the built-in timer of stat decay, allowing you to use a boost for as long as you need it.

How useful spicy stew is for any given skill depends on what boost you could have got without the stew, and how much effort it would have taken you to train an extra level in the skill instead. For many skills, if your level is (say) 65 you may find that the time and effort of collecting enough spices to be in with a good chance of a +5 boost - for that special one-off level 70 task you need to perform - is so much that it would have been almost as quick to train two extra levels to 67 and collect enough spices for a +3 boost, which you are likely to need far fewer attempts to get. Of course, you would also then have the extra levels and not need to train them again. Whether it is worth it depends also on what alternative boosts were available. For example, Smithing or Herblore can be raised +2 at reasonable cost with a mature Dwarven Stout or Greenman's Ale, but beyond that there is only spicy stew, so aiming for the +3, +4 and +5 are valuable uses for the stew since one or two extra bonus levels can allow you to make that special item or potion you need. For Agility and Thieving on the other hand, +5 and +4 boosts are easily obtainable with pies or Summoning scrolls, so the stew is of relatively little value for these skills.

Probability
Probability of getting at least x boost:

* Important note about +6 boosts: The RuneScape Knowledge Base states the maximum effect of a 3-dose stew to be +6 to -6. Not surprisingly, a number of players have tried hard to obtain this +6 boost and some have reported making hundreds of trials without success. The +6 bonus appears to have been made much rarer than the +5 bonus which is relatively common. It would seem likely that the +6/-6 effect is so rare that it can be ignored. For that reason, this article is written as if +6/-6 does not happen, because even though it does in freak cases, it is not of any practical use. +6 boosts were common several years ago, but appear to happen less often due to an unknown update.