The Evolution Of Combat, also called EOC, is a complete rework of how RuneScape combat works. This update is set up as a beta for users who want to test it out early, signups for which were open from 1 June 2012 to 19 June 2012. Currently, Jagex has not released any information about when the Evolution of Combat will be released into the game.
Entering the Beta
The beta servers can be accessed here. This is browser-based play, swiftkit can also be used. The login screen is as normal, and will take players into the lobby. If players wish to play with their main game character, they should click the "Import" button (pictured above) at the bottom left of the screen. If they do not click on this link, they will start the beta with a basic character.
Some effects include damage over time (DoT) and temporary damage boosts.  The damage over time effects include burn and bleed, similar to the current poison effect.
General changes to equipment
- All weapons of the same equipment tier (for example, all rune weapons) have had their stats adjusted in order to have roughly the same damage per second (DPS) value. Slower weapons such as rune spears and rune battleaxes are as effective in combat as faster weapons such as rune scimitars and rune daggers. This has essentially rendered the concept of different weapons useless; however slow but powerful weapons are still useful in certain PvP situations where it is necessary to deal a high amount of damage quickly.  Two-handed weapons have a 50% higher DPS than one-handed weapons of the same tier, to compensate for the lack of an off-hand item.
- Many, if not all, pieces of armour boost lifepoints, in a similar manner as torva, pernix, and virtus armours. However, the boosts are much more substantial; players who equip armour sets that are appropriate for their levels receive as much as 90% of their total lifepoint pool from their armour - more if wielding a shield. Before release of the beta, it was expected that a player with maxed combat stats and the best gear would have about 15,000 life points, most of it coming from their armour. However, thus far no equipment has been released that gives this high of a bonus to lifepoints.
- The ability to simultaneously wield two one-handed weapons (called "dual-wielding") was released. Special off-hand versions of many existing weapons have been created; these are separate from existing "main-hand" weapons and will require separate purchase or creation. It is possible to wield two one-handed weapons of different styles (such as a one-handed sword and a one-handed crossbow); however, it is only possible to use abilities of the style of weapon that is equipped in the main hand. Dual-wielded weapons have roughly the same DPS rating as two-handed weapons of the same tiers.
- All existing magical staves have been changed to be two-handed weapons, which sacrifice speed for extra damage. New wands have been released that act as one-handed staves. Additionally, off-hand magical equipment called orbs have been released that allow players to dual-wield Magic spells.
- All melee weapons are able to train Attack, Strength, and Defence. Rangers and Mages may choose to gain purely Defence experience.
- Armour equipped by players no longer has specific weaknesses to stab, slash, or crush attacks that are made by other players. Monsters continue to have weaknesses to specific attack types. Additionally, some monsters have weaknesses to specific Magic spell elements, such as water spells.
- While it is possible to switch armour types during combat, doing so is not recommended as it will incur a significant cooldown penalty to all abilities.
Changes to specific items
- Poison, instead of being applied to a weapon (commonly on daggers or spears), is consumed, allowing any wielded weapon to poison foes.
- Magic blastboxes and celestial surgeboxes provide unlimited air runes in the off-hand slot, instead of storing runes for combat spells. As both boxes are Dungeoneering-only items, they have been removed from the rest of the game, and any players who purchased them from the rewards trader had their tokens refunded. The runes are refunded upon logging into beta for the first time.
- The Inspiration aura affects the adrenaline bar instead of the special attack bar.
- As they have lost their special attacks, all four godswords are functionally equivalent.  However, their stats were increased to compensate. 
- Barrows equipment and Void Knight equipment still retain their set effects.  However, they only trigger on auto-attacks, not when abilities are used. 
- Enhanced excalibur has lost special attack. The weapon itself has had its combat stats improved to match those of the abyssal whip. It is now also an offhand-only weapon.
- Two-handed crossbows (such as the existing Karil's crossbow) have been added. They are the Ranged equivalents of two-handed swords. Like many existing crossbows, they are created using the Smithing and Fletching skills.
- The ring of kinship's class bonuses while Dungeoneering has been adjusted to fit with the combat update. 
- Much more Ranged and Magic armour has been released. Among others, rangers have received cockroach armour, and mages will have received spider-silk robes and bat wing robes.
- Longbows will receive defensive bonuses and lifepoint boosts.
- The abyssal vine whip's stats have received a boost.
- Untradable potions such as extreme potions and overloads are usable in the Wilderness.
- The ring of vigour allows players to retain 5% of the adrenaline bar after using an ultimate ability, instead of the bar draining to 0%.
- The Bandos armour set has been expanded to include a helm, a shield, and gloves. Armadyl armour has been upgraded with gloves, a buckler and boots.
- Some equipment has had their skill requirements adjusted for balancing purposes. For example, rune equipment requires level 50 Attack to wield the weapons and level 50 Defence to wear the armour.
- Crystal Equipment retains the same bonuses independent of degradation status.
- All dominion gloves are now wielded in both hands and are now the equivalent of a level 80 weapon of their combat style. They still have their previous special effects.
Changes to combat skills
- The formula for determining a player's combat level has been changed to be much simpler: it is , where is a player's highest skill level among Attack, Strength, Magic, and Ranged. Consequently, players will start off at combat level 4, and the maximum combat level is 200. Constitution, Prayer, and Summoning levels no longer affect combat levels.
- This can lead to Constitution Pures. Using xp lamps from SoF and Random events a player can level up constitution to 99. Along with leveling up Prayer and Summoning this can be a very deadly foe against low levels in PvP.
- The amounts of lifepoints healed by a given piece of food is tied to a player's Constitution level. For example, a player with 50 Constitution may eat sharks, but will not receive any more lifepoints from them than lobsters.
- Protection Prayers and deflection Curses may now be hit through by monsters as well as players. These prayers now only reduce the amount of damage you take. Currently, the damage reflected is still roughly treated as normal, often reflecting for the usual 2 digit hits. Furthermore, prayers like Piety and Augury no longer show exact percentages of increase. The "Show stat changes" button has also been removed.
- The Defence skill has received multiple updates to make it more important in combat. Among these upgrades are a range of Defence-related abilities for players wielding a shield (or the equivalent for rangers and mages) as well as very large lifepoints boosts from armour.
- Two new curses, Anguish and Torment, have been released for the Ancient Curses. They act as Ranged and Magic versions of Turmoil, respectively, and all three prayers unlock at the same Prayer level.
- Sap and Leech curses have been updated. Leech Special Attack, has become Leech Adrenaline, which works on the adrenaline bar instead of the special attack bar.
- Rigour and Augury unlock along with Piety with both Prayer levels changed to 70. Players who purchased Rigour and/or Augury from the rewards trader at Daemonheim have had their tokens refunded.
- Rune requirements for spells have changed, and on the whole are significantly lower. For example, it is possible to cast Wind Surge using only air runes, instead of air runes, death runes, and blood runes. Ice Barrage costs two blood runes and five water runes. Rush and Burst spells use death runes, whereas Blitz and Barrage spells use blood runes. Additionally, only auto-attacks consume ammunition for rangers and runes for mages; abilities do not consume ammunition.
- The lunar spell Energy Transfer has been removed from the game.
- Mage Arena Spells have been removed.
- Training the Slayer skill does not have a dramatic change in speed.
- When first introduced, combat XP was reduced when fighting enemies 30 levels below your combat level, this has since been removed. 
- ^ Combat: Buffs and Weaknesses. Jagex.*
- ^ a b c d e f g h i Jagex Talks Combat - More Info. Jagex.*
- ^ Dual Wields VS 2Hands??. Jagex.*
- ^ a b c d e f Og Blog: The Final Challenges. Jagex.*
- ^ a b Clarification On Combat Level. Jagex. “A maxed out player in the best gear will have 990 Lifepoints from their Constituion, but will be getting around 15,000 Lifepoints from their equipment.”*
- ^ a b RuneScape - News - Evolution of Combat: Dual Wielding. Jagex.*
- ^ Clarification On Dual-Wielding. Jagex.*
- ^ a b c Behind the Scenes #6 - fingers, fighting and a special reveal!. runescape.*
- ^ Dual Wields VS 2Hands??. Jagex.*
- ^ a b c d e f g h i j k l m n o Jagex Talks Combat - More Info. Jagex.*
- ^ Og Blog: Tradition and Challenge. Jagex.*
- ^ Mod Emilee. Your Feedback - Changes Your Feedback - Changes Your Feedback - Changes Your Feedback - Changes Your Feedback - Changes Your Feedback - Changes You. Jagex.*