Howcome movespeed bonuses won't stack?

I set "Move Speed Bonuses Stack" to true in the gameplay constants but it didn't do anything. Two boots of speed don't make you any faster than one. Two items with Endurance aura have the same effect as one. Endurance aura stacks with boots of speed, but it does that regardless of whether that gameplay constant is true or false.

Unfortunately I'm not sure exactly as to why they don't stack. I do know that aura effects have never stacked (if they are the same aura, I mean).
What may work is creating triggers handling specific buffs that a unit receives and using SetUnitMoveSpeed(unit, newspeed) to manage its speed. In order to keep it multi-instanceable without using globals you can use SetUnitCustomValue(integerofspeed) to track what its current movespeed is.

EDIT: What I mean is, assign unique Buffs to each item or ability that gives a movement speed bonus. Then you can detect which bonuses it should get and use what I said above to adjust its speed up or down.

You can find both the current and default movement speeds anyway using triggers.

The Set/Get Move/DefaultMove natives do not play nice with others. If possible stick to buffs or effects or however things work in that scary object editor place I don't go near.

Hmmph. There is so much crap in the editor that just plain doesn't work.

So if I wanted boots of speed to be able to stack couldn't I just make dummy boots that do nothing and then have a trigger so each time a hero aquires the boots their movespeed becomes current movespeed + 50, and whenever they drop the item -50?

accualy i think they used this to prevent games in melee where a unit can just mass boots and health pendants and do hit and runs with like pitlord

anyway that method would work, assuming that each boot adds 50 movement, and you just level it when the unit aquires and delevel when unit loses

Actually, I would strongly advise against using the set movespeed function. It just doesn't play nice with other effects, for example getting bloodlust (which increases speed) will probably mess up your speed.

Non-stacking movespeed is just one out of many many reasons I decided to write an entirely custom attribute system. What I do is to give each hero a hidden boots of speed ability with many levels that goes from +5, +10, +15 all the way up to +520. Then I give each hero 5 movespeed and adjust their real speed by modifying the level of their boots of speed ability. So if in my map, if I want to, a hero can gain movespeed both from, lets say their Elven boot and their Magic Helmet.

However, this kind of system requires quite a bit of work.

karukef, you think bloodlust would reset the movespeed of the unit when it is cast on the unit or when it runs out or cause it to have permanent bloodlusted speed or what? What do you mean it will "mess up my speed"?

Why not +1,+2,+4,+8...? only need 8 or 9 abilities that way.
Or +5,+10,+20,+40 if that's all the granularity you need.
Edit: OH, levels. not different abilities.

Do different levels of movement speed abilities actually work? Most item abilities don't work above level 1.

I believe they mean that a % increment in movement speed includes the bonuses you have given through triggers

So like if you have a movespeed of 200 and a trigger makes you have 250, and a bloodlust spell makes you 10% faster you will end up being 275 instead of just 270? If that is all I am not too worried.

Health, HP Regen, Mana, and Mana Regen don't go above level 1. Damage, Attack Speed, Move Speed, and Armor can go above level 1. I don't know about the other ones.

Cool that is good to know. What other ones are there, besides the hero primaries?

But you even if you do have an item with multiple levels of an ability you can't actually make it use the higher levels can you? karukef is talking about applying the item ability directly to the unit and levelling that right?

karukef, could you explain exactly what you meant by triggering movespeed not playing nice with effects like bloodlust?

Um as far as I know boots of speed can stack when setting the Movement speed stacking option to ON inside gameplay constants