How would I find the a patent? I'm curious, because I plan on developing an RPG in the vein of that sort of battle system.
A few comments:
The question is whether the "linear motion battle system" you intend to build infringes any issued US Patents. These could be owned by Namco Bandai or other companies.
Because modern technology is complex, determining infringement is complex. If you are concerned that patents may have been issued on the linear motion battle system which you intend to build, you should have a prior art search done by a patent agent (or a patent attorney) before building it. The goal would be to determine whether you need to invent around any specific patents.
A number of active contributors to Ask Patents are patent agents or patent attorneys who do prior art searches on a regular basis. You should feel free to reach out any of them directly to discuss your project. Most would give a quick initial consultation for free to discuss fees and scope of work.
That said, here is a list of recent issued patents assigned to Namco Bandai which involve linear motion. You can use Google Patent search to read these patents. You would want to pay particular attention to the claims of the patents, not the title or the abstract, to determine what invention specifically has been claimed by Namco.
44 Recent US Patents assigned to Namco related to Linear Motion
US8262477B2 Information storage medium, game device, and method of controlling game device
US8210941B2 Medium position detection device, display device, game device and token game device
US8142277B2 Program, game system, and movement control method for assisting a user to position a game object
US7922584B2 Image generation method and information storage medium with program for video game in which operation of the controller beyond a predetermined angle causes a character to attack
US7918729B2 Program product, image generation system, and image generation method
US7881521B2 Rotational image generation method, program, and information storage medium and virtual camera
US7796132B1 Image generation system and program
US7724255B2 Program, information storage medium, and image generation system
US7722450B2 Game system, program, and information storage medium
US7710419B2 Program, information storage medium, and image generation system
US7566273B2 Game system and image generating method
US7367887B2 Game apparatus, storage medium, and computer program that adjust level of game difficulty
US7341188B2 Position detection system, game system, and control method for position detection system
US7312804B2 Program product, image generation method and image generation system
US7281981B2 Image generation method, program, and information storage medium
US7129945B2 Image generation method, program and information storage medium
US7116334B2 Game system and image creating method
US7088366B2 Image generation method, program, and information storage medium
US7091972B2 Image generation of shadows utilizing a modifier volume gap region
US7046242B2 Game system, program and image generating method
US7042463B2 Image generating system and program
US7014562B2 Video game machine and after-image display method of video game machine
US7015908B2 Image generation system and information storage medium
US6927777B2 Image generating system and program
US6891534B2 Method, apparatus, storage medium, program, and program product for generating image data of virtual space
US6890261B2 Game system, program and image generation method
US6850242B1 Image generating system and program
US6828969B2 Game system, program and image generating method
US6798402B1 Received-light pattern detection apparatus
US6795082B2 Image generation system, program and image generation method
US6749514B1 Game system and information storage medium
US6663491B2 Game apparatus, storage medium and computer program that adjust tempo of sound
US6642917B1 Sign perception system, game system, and computer-readable recording medium having game program recorded thereon
US6537153B2 Game system, program and image generating method
US6448970B1 Image generation apparatus for causing movement of moving body based on flow data for a fluid set on a course, and information storage medium
US6388667B1 Image generation device and information storage medium
US6320988B1 Skeleton model shape transformation method, image synthesizing apparatus, and information storage medium
US6206783B1 Control input device and game system
US6139473A Action input device for simulator, and simulator using the same
US5997303A Rotary sliding device and a simulator using the same
US5704837A Video game steering system causing translation, rotation and curvilinear motion on the object
US5723802A Music instrument which generates a rhythm EKG
US5707060A Medal dropping game machine
US5598516A Image synthesizing system and video game apparatus using the same
There are many types of searches. A novelty search, for example, looks for publications of any kind from any place and time that would show that your great idea is not new and non-obvious. You do that to gauge if your idea might be patentable.
On the other hand, if you are planning to build a product and are concerned about infringing someone else's patent, you would do a freedom to operate search. Only the claims of issued and in-force patents in the countries you plan to sell into are relevant. But, in a freedom to operate search, it isn't only the clever part of your product plans that are at issue. You could invent a car that flys and its tire treads can infringe a Firestone tread pattern utility patent. Of course, switching to non-infringing tires later is easier than redesigning the core of a product.
Although no particular license is required for any searching, people who are serious about freedom to operate searches often want an accompanying opinion that you are clear to make and ship. Only an attorney can provide that since it essentially predicts you having a good outcome if you end up in court. They, rightly, charge a lot for that "insurance policy".