In the days of the telegraph, human operators sent telecommunications by hand using morse code. Each person had their own cadence and style of sending messages; the styles were so unique that another operator could unfailingly distinguish which person sent a message simply by hearing the message arrive. This style was called the operator's <i>fist</i>. A careful perusal of screenshots from different upcoming games shows similar "fists" emerging for the game engine driving them. Over the last several years, game engine licensing has increased in popularity as more and more is expected of a game and as the costs increase accordingly. Two of the major licensers are id Software, with their Doom Engine and Epic Software, with their Unreal Engine. <h>The Test</h> To even the playing field, all of the screenshots are from pseudo-futuristic nightmare worlds in which soldiers battle aliens. We can thank the inventiveness of the video game publishers for lending validity to this experiment. Each of the screenshots below are from one of the two engine mentioned above. Can you tell which? <img attachment="enemy_territory_quake_wars_1.jpeg" align="center" class="frame" caption="(A)"> <img attachment="enemy_territory_quake_wars_2.jpeg" align="center" class="frame" caption="(B)"> <img attachment="gears_of_war_1.jpeg" align="center" class="frame" caption="(C)"> <img attachment="gears_of_war_2.jpeg" align="center" class="frame" caption="(D)"> <img attachment="prey_2.jpeg" align="center" class="frame" caption="(E)"> <h>The Answers</h> Before you read the answers, note how similar the game titles are: the first four shots have human soldiers fighting alien armies. The aliens look strikingly similar. Most of the weapons are ridiculously oversized. It's only the <i>style</i> of the engine that lets us tell them apart. (A) and (B) are from <i>Enemy Territory - Quake Wars</i>, which uses the Doom Engine. (C) and (D) are from <i>Gears of War</i>, using the Unreal Engine and (E) is from <i>Prey</i>, which uses the Doom Engine. Why games using the Unreal Engine tend to have a more "cartoony" look---oversized weapons, child-sized heads atop enormous bodies, usually encased in full-body armor---while games using the Doom Engine tend to the more grotesque, is not clear. Even the Prey screenshot, a game with a completely different approach to gravity and gameplay, includes an alien that just <i>screams</i> Doom Engine. The results don't necessarily mean anything; it's just interesting to see if you can tell which game engine drives a game just from a quick glance at a screenshot.