They are not always needed if you have platted or buffet dinner served. I would judge it more on what is actually going on your table!
And here is a full table with...
All three options look very elegant! But chargers can over do it!
This table just looks messy! Do not do petals AND chargers. There is just too much going on and we cant even see what the centerpiece looks like. Also when you do chargers, please do not place the napkins in the glasses. Place them on or underneith the chargers.
Sorry for the blur on this one... This table needed chargers. Its very beautiful and simple but chargers would have brought in a touch of elegance.
There are also many types of chargers. You can get them in round and square and in just about every color. They range from $1-25 a piece wither you buy or rent them. If you have 100 guests you are looking at a difference of $100 and $2,500.
I believe that if you have alot going on your tables you dont need chargers. If you are planning simple centerpieces simple linens then yes, add the chargers!
If you are not planning on serving buffet or plated dinner, do not use chargers! It give the impression that you are planning on feeding guests. If you are just doing an appitizer reception, stick with a beautiful centerpiece and smaller tables.