At the start of the demonstration I was staring at two screens - two screens that showed the same game but with a different character. Yes, Original Sin can be played in multiplayer mode - it features two playable characters that can be controlled by two different players. In this cooperative multiplayer mode, a maximum of 4 players can play, but there are only two lead characters - two more players can play using mercenaries that are be hired in the game. However, the game can also be played single-player, where the player controls the whole party.

Playable characters can summon a summoning doll or an elemental, but each of them can only summon one at the time, making the maximum party size 8. The summoned creature is not controllable but will follow the character that summoned it and assist in combat, similar to the summoned creatues in Divinity 2. Enemies are not automatically leveled to your level, but combat will be scaled depending on how many players are participating in the game as fights would otherwise become too easy or too hard.

[...] The conversation starts with one of the characters who gets a list of options to choose from, just like we are used to in an RPG. The other player does not see the options but will see the choice; based on that choice the person you are talking to responds and the second player gets to choose from a list of answers. The decision on what to do next is not decided by one of the characters, but both have to agree. If they do not, this is discussed and a virtual dice is thrown in the background with the result modified with the charisma that each of the characters has to determine who wins the conversation. At the moment the developers are also thinking about adding the option to intimidate the other party member, which would result in the virtual dice being modified based on the strength of the characters. Or, Intelligence could be used to win a conversation with arguments. This has not been finalized yet, but when implemented well, this could add a lot to the multiplayer experience of the game. [...] Choices in conversation can also make factions hostile or friendly towards you, making some parts of the game easier or more difficult.

[...] Every time you level up, the four basic stats can be modified: strength, intelligence, dexterity and charisma. All other statistics are derived from these and equipment you are carrying and cannot be modified directly. This system is based on what was used in the first Divinity.

Next to modifying the stats when leveling up it is also possible to choose a skill. There are six schools of skills, four of which are magical schools based on the elements of nature: Earth, Wind, Fire and Water. Your opponents will have more or less resistance to these skills, rendering some skills useless on some creatures. Fire elements for example will have a very high resistance against fire but a very low resistance against water.

[...] The two protagonists will each have a reputation that is changed based on what they do in the world. The game starts with nobody recognizing your character, but your actions in the world will increase your reputation and change their interaction with you. This is independent on whether you do good or evil - for that there is alignment, which determines the attitude of people towards you and changes depending on you doing good or bad. If you like to play the bad guy (or girl), at a certain point the merchants won't like you anymore and are not willing to trade. Bandits like you though, so if you can find a trader who likes bandits that should not be an issue.

[...] Combat is turn-based and takes action points. Each action like moving, fighting, using a skill or equipping stuff will take action points. The switch to turn-based was made because they wanted to add something extra to the game. [...] For those who are less interested in fighting there will also be possibilities to talk yourself out of combat, which will require certain levels of your statistics.

In combat, your skills will be frequently used and, like with items, skills can be combined to do even more damage. When someone is on fire, the damage inflicted can be increased by putting another skill on them like a heat wave.

The terrain can be used in combat as well. A skill that makes it rain can be used and depending on the terrain this could form a puddle of water. If your opponent stands in that puddle, using the electricity skill will do more damage than without the water. But if one of the two characters is on fire, making it rain will put the fire out.

[...] Original Sin can be modded. The same toolset as is used by the developers will be delivered as part of the game.​