I was thinking about adding a system to my game that includes pure attack and defense items. Items have varying amounts of either attack or defense but never both.

Players will have a limited pool of attack and defense points. Attack and defense points are mutually exclusive. Equipping an item with attack will drain your defense pool by that exact amount of attack, and vice versa.

What are your thoughts on this?

Hmm... A few thoughts:

First of all, you haven't given much detail regarding your game, which may affect how your pool system feels in practice--I don't even know whether these items are being equipped to humanoid avatars, or ships, or towers, or something else entirely. For now I'm assuming a humanoid avatar in a fantasy setting.

What, then, is the function of the pools of points? Do they just limit what the player may or may not equip? If so, then do I take it that there is no other limit on what a player may equip? After all, if the player may equip only one weapon, one necklace, two rings, etc., as is commonly the case, then how much does this system affect what they may or may not equip? If it is the only limiting factor, then does that mean that the player may equip ten swords, or five shields, so long as they have sufficient points in their pool?

Although it could be interesting, no, a player can't equip ten swords. I'm not saying this is definitely going in, I'm still in early development stages but I was thinking of increasing pool sizes as a form of leveling.

It's a sci-fi game so equipment will be mainly implants, guns,shield generators, high tech armor, etc. All items will have categories within their type and for the most part you'd only be able to equip one per category, so you'd have to manage your offensive and defensive items efficiently.

You could equip items of varying power at any pool size. Of coarse with smaller pools, you'd be able to equip a lesser amount of powerful items.

It's a sci-fi game so equipment will be mainly implants, guns,shield generators, high tech armor, etc. All items will have categories within their type and for the most part you'd only be able to equip one per category, so you'd have to manage your offensive and defensive items efficiently.

Ah, this clarifies things for me somewhat--thank you.

Hmm... So I'm guessing that the player will get a choice as to how big each pool grows--one player might invest more in the attack than the defence pool, allowing them to equip a greater number of or more powerful defensive gear, for example--is that correct? That could be somewhat interesting, I think.

(Which prompts a thought: it might be more intuitive if equipping attack items drained the attack pool and defence items the defence pool; since the pools only affect what one may equip, there doesn't see.)

Otherwise... The only thing that really comes to mind offhand is that it seems a little limited compared to systems that allow the player to advance various skill-types that affect which items they may use, or how effectively they use them. If such a system is also in place, then I'm not sure that this one isn't a little superfluous. Of course, if simplicity is what you're aiming for, then this could well be a good idea.

Perhaps it's time to prototype it, however--let people try it out and try it out yourself--and see how it works in practice.

The reason I wanted to make attack drain the defense pool is because I wanted a balance, trade off system. I guess this would only work of you could equip multiple items until your pools are depleted though, since equipping an item of attack or defense in limited slots is already a trade off. Maybe I'll use the attack/defense system for item/implant upgrades instead. I think it would make more sense that way. You could just keep upgrading the items until one of your pools is depleted. I'm not sure if I want to just increase pools at the same rate, or let the player choose yet.

The reason I wanted to make attack drain the defense pool is because I wanted a balance, trade off system.

Do you mean a trade-off between attack and defence, such that taking attack items reduces one's defensive capabilities? If so, then as far as I understand the system that you've outlined, it doesn't seem as though it would actually produce that trade-off: since items draw from one pool or the other, and the pools aren't used for anything else, taking attack items doesn't affect how many defence items one can take, and vice versa.

For example, let's say that the player has an attack pool of ten, and a defence pool of five. They then take an attack item of value five, depleting their defence pool to zero. But since defence items draw from the attack pool, which still has a value of ten, taking the attack item has no effect on how many defence items may be taken. As a result, the "defence" pool is effectively the "attack" pool, and vice versa.

Yeah, I think maybe instead of two pools, I should have 1 pool with a slider that slides towards attack or defense when items are equipped.

That could work. ^_^

Come to that, you may not even need the slider: simply have a pool, points from which are used by equipping items, thus naturally limiting what one may equip with each item added.

Maybe I should scale all equipped item's power depending on how many items of either attack or defense are equipped? So a lot of defense items would increase the effectiveness of all other defense items while also lowering the effectiveness of all equipped attack items.

You might be able to do something interesting with two separate pools and then a wildcard pool. (Let's call them "energy" since it's a sci-fi setting and give them colors to keep track of them.) "Red energy" can only power offensive gear, and "blue energy" can only power defensive gear, and "purple energy" can power *anything* but is less efficient or costs more.

The result is an efficiency/flexibility tradeoff. When upgrading your energy pools, you can put your points into red and blue, which is the most efficient use of your upgrade points, but the downside is that when circumstances change (short-term or long-term) you don't have as much freedom to change your equipment. On the other hand, purple energy gives complete flexibility, but maybe it costs 1.5 times as much EXP to purchase a unit of purple energy. (Not 1.0, because it'd be a no-brainer, and not 2.0, because it'd be a no-brainer in the other direction, but somewhere in between.) So you certainly want to invest in a buffer of *some* purple energy, but you also don't want *all* purple energy because you'd be comparatively underpowered for your level.

(Note also that this system doesn't limit you to two basic "colors", since the red and blue pools don't interact. You could have other kinds of equipment, too, with its own kind of energy. So if there were four kinds of equipment, you'd have four colors and then the wildcard color, which can power anything but should, in this scenario, cost even more than before.)