The mechanics in Dungeon World are different from most systems which use a Dice Roll verse an ever-changing Target Number, Dungeon World uses a mechanic that you roll against a Target that never changes and success is based on the Roll result. Instead of a d20+modifiers being rolled DW uses 2d6+modifier, a result of 10 or more is a complete success, 7-9 is success with a consequence, and 6 or less is a failure. There are no rounds, no initiative, no defined movement, it is much more cinematic. In D&D or say Pathfinder you really couldn't have level 1 characters encounter a hostile red dragon, in Dungeon World, you could. Actual game play has the GM/DM describe a situation, the player describes what he'll try to do and roll his dice, and the GM will tell him the result. Here is a Player Basic Move Called Hack and Slash When you attack an enemy in melee , roll+Str. On a 10+ you deal your damage to the enemy and avoid their attack. At your option, you may choose to do +1d6 damage but expose yourself to the enemy's attack. On a 7-9, you deal your damage to the enemy and the enemy makes an attack against you. The enemy makes an Attack against you means it delivers it's damage, there is no Roll, in DW the GM doesn't Roll ANY DICE. There several Basic Moves that cover just about anything the player wants to try. I hope this brief explanation helps. This is an Imaginative Role Player's Dream, simply put "You Play to See What Happens"... -Ajax