Any ideas on how to allow a player in a 2D (side scrolling platformer) to execute complex interaction with the environment without having to map every key on the keyboard (Going for a very simple layout, 4 direction keys + 1 to 5 action keys). The character needs to be able to engage in skilled combat with and without weapons, including the use of a sword (Prince of Persia comes to mind as a skill based sword fighting system), execute complex acrobatics (rolls, flips, wall jumps, climbing, sneaking), be able to use a number of different item and manipulate objects in the environment (Throw switches, possibly push and pull things). So far the only way I can think of to implement this elegently(It''s mainly an action game so the player shouldn''t have to remember dozens of keys to play) is to use the behavoir approach seen in Little Big Adventure (Relentless in USA) whereby the player can switch between different behavoir modes. In LBA the modes were "normal": Walk about and interact with objects like switchs, talk to people. "sporty": Running, jumping and acrobatics. "aggressive": Fighting. "descriet": sneaking.

Why not have an intelligent mouse? For example, if they click on a wall, then what action are you going to take? You wouldn''t talk to it, get it, or flip it, so that leaves jumping on it. You see an NPC, you will either want to attack it or talk to it. Well, if its agressive you will attack it of course since it won''t talk. If it is peaceful instead, then you have a choice. Most of the time you will be talking to it. You have to think about what the player will want to do and under what circumstances. Like you could make it where the player could attack the peaceful character by holding ctrl and clicking it. This would be good because the player wouldn''t need to be in a hurry if the NPC is peaceful. Switches, what else can you do with them? You always flip them. Ok, so manipulating objects? That''s easy, just have a primary use (again think about which will be needed the fastest) like drinking a potion. Then you can add a secondary use of the item if you really need it, but most situations can be handled elegantly by something instead of pushing a button while clicking the item. For example, say I want to throw the potion at something. Well, common sense would be to drag it and drop it at a wall/monster/whatever.

Anyway, the player isn''t going to be doing every action on every thing in the environment. Map what they will want to do most of the time( or will need to do fastest [battles] ) to the intelligent mouse. From there you can add alt keys and stuff to change what it does. I realize that I wrote up all this and kept referring to the mouse. I felt that this expressed the idea better. The concept would be the same, but instead you have an intelligent action key. This might be something sort of like the "USE" or "MANIPULATE" key in some current FPSs.

I thought of using the mouse (when using tools in order to aim), however I don''t think I can use the mouse for movement/interaction (ala Diablo) since unlike Diablo my character needs to be able to execute a very large number of non-combat moves (acrobatic type movement)

Ok, you didn''t get it. In more simple terms try using a set of ''magic'' buttons. After all, you could do more than 2 things in a side scroller on the gameboy or nintendo.